Wandering throughout South America: Taxonomic revision of Tradescantia subg. Austrotradescantia (D.R.Hunt) M.Pell. (Commelinaceae)

Abstract I present the first taxonomic revision for T. subg. Austrotradescantia, based on extensive field, cultivation and herbaria studies. I accept 13 species, three of them (i.e. T. atlantica, T. hertweckii and T. tucumanensis) being described as new in the present study. I provide an identification key to the species, distribution maps, descriptions, comments, conservation assessments and illustrations for all species. The troublesome weed T. fluminensis has its specific limits clarified and its native range is presented so it can serve as a basis to better understanding its ecological requirements and to help control it throughout its invasive range. Furthermore, I highlight that T. mundula, a commonly neglected species closely related to T. fluminensis, might also represent a troublesome weed. Tradescantia mundula has been widely introduced in cultivation under the name T. albiflora and seems to have also escaped from cultivation. However, due to the hitherto poorly understood specific limits of T. fluminensis, T. mundula has been treated as a mere cultivar of T. fluminensis s.s.

from the Acknowledgments; for figure 18 replaced as a whole, the in-text citations to it were corrected as well. Removed images are: 3(C), 5(C, D), 12(A, C, G-I). Replaced images are: 18(entire plate), 32(A). The reason for replacement or removal is that these images were used by the author without explicit permission of the copyright owner. After publication, the author of the removed images Mr. L. Funez claimed a copyright violation, despite his being credited as the provider of the images in the paper. The author of the paper reported he had a verbal permission to use them from Mr. L. Funez, who denied that he had given such permission. Another copyright claim for these images came from Dr. G. Hassemer, a lead author of a paper published in the journal Phytotaxa (https://doi.org/10.11646/ phytotaxa.312.2.4) and its publisher Magnolia Press. Given these circumstances, the editors of PhytoKeys decided to remove the original version of the monograph and publish this corrected version, explaining the reasons for that in this present notice. Any and all nomenclatural acts (

Introduction
Commelinaceae is an economically important family, due to the ornamental value of many genera and by the great number of invasive species, especially in Commelina L. and Tradescantia L. emend M.Pell. (Hunt 2001;Burns 2008). Tradescantia, is the second largest genus in the family, with ca. 90 species (Pellegrini 2017). It is characterised by its actinomorphic flowers with six equal to subequal stamens, seeds with linear hilum and main florescences composed by a double-cincinni fused back to back, with each cincinni subtended by a frondose bract (Faden 1998;Panigo et al. 2011;Pellegrini 2017). Throughout the years, four infrageneric classifications were proposed for Tradescantia: Clarke (1881), Brückner (1930), Hunt (1975Hunt ( , 1980Hunt ( , 1986 and Pellegrini (2017). The current classification divides Tradescantia into five monophyletic subgenera (Hertweck and Pires 2014;Pellegrini 2017), further supported by micro-and macromorphological characters, anatomy, phytochemistry and cytology (Pellegrini 2017).
Tradescantia sect. Austrotradescantia was described by Hunt (1980), being composed of five species, based on the T. fluminensis Vell. species complex (sensu Woodson Jr. 1942) and as the only exclusively South American section of the genus, with its diversity centre in Southeastern Brazil (Hunt 1980). It was characterised by its prostrate stems, leaf-like to spathaceous cincinni bracts, free petals and stamens, dorsal embryotega and numerous and bimodal chromosomes (Jones and Jopling 1972;Hunt 1980). Other studies showed that the section also presented a rather peculiar phytochemical profile (Martínez and Martínez 1993) and stigmatic morphology (Owens and Kimmins 1981;Owens et al. 1984), which differentiated it from the remaining sections and species of the genus. Based on microand macromorphological characters, anatomy, phytochemistry and cytology characters and supported by the molecular evidence published by Hertweck and Pires (2014), Pellegrini (2017) elevated T. sect. Austrotradescantia to the subgeneric rank, also broadening and clarifying the group's morphological circumscription. Hunt (1980) originally included five species in the section, later (i.e. Hunt 2001) reducing T. blossfeldiana Mildbr. to a synonym of T. cerinthoides Kunth. Pellegrini et al. (2015) reestablished T. mundula Kunth and typified T. fluminensis Vell. and T. geniculata Vell., while dealing with the Tradescantia names in Flora fluminensis (Vellozo 1829(Vellozo , 1831. Pellegrini et al. (2016) (Büneker et al. 2017) and T. serrana Hassemer & Funez (in Hassemer et al. 2017) as new species for T. sect. Austrotradescantia. Nonetheless, in my new infrageneric classification for Tradescantia (i.e. Pellegrini 2017), I intentionally do not mention these names amongst the species accepted by me for T. subg. Austrotradescantia, as a way to imply that I consider these names to be synonymous with other species. In the overview for T. subg. Austrotradescantia, presented by me as part of the new infrageneric classification for Tradescantia (i.e. Pellegrini 2017), the subgenus hairs; style obconic at base and conic at apex, stigma punctate with type D papillae; seeds with costate testa and relatively inconspicuous embryotega; small bimodal and numerous chromosomes (n = 10-numerous); and a unique chemical profile (Pellegrini 2017). Two morphological groups are accepted for the subgenus, both supported by recent phylogenetic studies (Pellegrini 2017). The T. fluminensis group is composed of generally more delicate plants, with prostrate stems with ascending apex, indefinite bases, subpetiolate leaves, cincinni bracts saccate at base and white petals. Nonetheless, this group also includes the T. tenella complex, which possesses erect stems, definite base, flowers that range from white to pink, seeds with rugose testa and hilum shorter than half the length of the seeds. The species in the T. fluminensis group occur almost exclusively in Tropical and Subtropical Rainforests but are also commonly found growing as weedy plants throughout their distribution range (Pellegrini 2017). The T. crassula group is composed of succulent plants, with erect stems, complicate leaves, cincinni bracts not saccate at base, petals ranging from white to pink to lilac and seeds cleft towards the embryotega. These species are intimately related to the two southern domains of South America, characterised by open and/or drier vegetation formations: the Chaco (which is part of the Dry Diagonal) and the Pampa (which is mostly represented by grasslands). The species from the T. crassula group are morphologically very similar due to many overlapping morphological characters; with indumentum type and distribution in the sepals being the most useful character for separating its species.
Recommendations for field collectors. As widely known, Commelinaceae is a group where flowers are generally poorly preserved in herbarium specimens, making it especially difficult to work with (Faden 1991). In T. subg. Austrotradescantia, taxonomy relies greatly on indumentum characters, with its type, distribution and colouration being especially important. Moreover, the indumentum in the pedicels and sepals seems to be constant within the same species and variable between different species. Thus, I recommend that field workers pay special attention to the plant's indumentum, collect young and mature branches in order to correctly characterise the species (since features like the presence of a subpetiole and shape of the leaf-blades might vary during development), record the colouration of vegetative and reproductive organs and, whenever possible, attach photographs to the herbarium sheets. Images are of great aid and can help identify even the most incomplete and damaged specimens. Furthermore, whenever possible, spirit collections and live specimens for cultivation are welcome, since they enable the proper study of the delicate flowers of these plants and live specimens might help us understand their morphological variation and plasticity.
Roots, stems and growth forms. As stated by Pellegrini (2017), most Tradescantia species are perennial herbs, all of them lacking rhizomes. In T. subg. Austrotradescantia, the roots are always thin and fibrous and never tuberised as in many species of the other four subgenera. In the mat-forming species, roots are produced throughout the stems, whenever they touch the substrate. In the species with erect stems, roots are restricted to the basal-most nodes of the plants. The stems can vary in posture, from prostrate (generally with ascending apex) to erect, while the branching pattern ranges from unbranched to little branched at the base or branched to densely branched in the upper half. The leaf-opposed line of uniseriate hairs is generally observable in most species, except T. seubertiana which is completely glabrous. Nonetheless, it is not constant in any of the remaining species, being either present or absent, depending on the specimen or even on the maturation and/or position of the stem (i.e. younger shoots tend to produce this leaf-opposed line of uniseriate hairs, which is generally lost with age). Finally, in species densely covered by indumentum, such as T. cerinthoides, T. chrysophylla, T. cymbispatha and T. mundula, the leaf-opposed line of uniseriate hairs is generally absent or, if present, is very hard to differentiate from the dense surrounding indumentum.
Indumentum. The indumentum in T. subg. Austrotradescantia is consistently composed of uniseriate hairs, ranging from eglandular to glandular (Fig. 2C-F). Special attention should be also given to the prickle-hairs that are generally 2-celled and pre- sent at the margins of the leaf-sheaths and blades (Fig. 2B,E), but consistently absent only in T. seubertiana ( Fig. 2A). Glandular hairs can be found in the vegetative organs of T. cerinthoides but are consistently found in the pedicels of most species and the sepals of many (Fig. 2F). As aforementioned, indumentum morphology is key for species delimitation in T. subg. Austrotradescantia, being easily observed most of the time. Nonetheless, some species are especially susceptible to the excessive heat of some plant driers, which can lead to an artificial loss of hairs. Two good examples are T. cymbispatha and T. mundula, where the first has been observed to sometimes lose its characteristic dense strigose indumentum in some excessively dried specimens from Argentina and Southern Brazil, while the second presents delicate sepal hairs that commonly fall during the drying process. However, due to the almost unique combination of morphological characters (e.g. sessile and succulent leaves, with generally elliptic blades and sepals lacking dorsal keels and evenly velutine), T. cymbispatha can be easily identified even when the vegetative hairs are almost completely lost during the excessive drying process. In T. mundula, this partial loss of sepal hairs can lead to confusion in the identification of dried specimens, making it even more similar to T. fluminensis s.s.
Leaves. The leaves in T. subg. Austrotradescantia can range from distichously-to spirally-alternate, sometimes in the same species (e.g. most species belonging to T. crassula group), from sessile to distinctively subpetiolate (Fig. 3), but always presenting an asymmetric base (Fig. 3). The blades tend to decrease in overall size towards the apex of the stem, while subpetioles decrease in length. Alternatively, the basal-most leaves  tend to possess wider bases when compared to the leaves towards the apex of the stem. Subpetioles are restricted to some species in the T. fluminensis group, with sessile leaves being plesiomorphic in Commelinaceae (Pellegrini 2017). The apex of the leaf-blades is generally acute but can also range from acute to caudate or obtuse (Fig. 3). The base of the leaf-blades can range from cuneate to obtuse to cordate or from truncate to amplexicaulous (Fig. 3). Finally, the ptyxis can either be convolute or involute, with convolute leaves being restricted to the T. crassula group and involute leaves restricted to the T. fluminensis group.
Variegation. Striped leaves have long been observed, described and utilised for species delimitation in the family. In some species (e.g. T. soconuscana Matuda and T. zebrina Heynh. ex Bosse and their relatives), it is a marking feature that greatly aids their recognition (Pellegrini 2017). According to my anatomical observations and ongoing studies on the matter, the silver stripes in Commelinaceae seem to consist of aerenchymatous tissue that might help understorey plants increase the amount of light they are able to absorb, by directing light through reflection to the inside of the chlorophyllate parenchyma (unpublished data). Nonetheless, this feature has been observed not to be constant in most taxa of the family, being environmentally controlled in at least Buforrestia C.B.Clarke, Dichorisandra J.C.Mikan, Floscopa Lour., Plowmanianthus Faden & C.R.Hardy and Siderasis Raf. emend. M.Pell. & Faden (pers. observ.). In Tradescantia, this feature seems to be phylogenetically related (at least to some degree), since it is only known to occur in T. subg. Campelia (Pellegrini 2017). In T. subg. Austrotradescantia, a myriad of cultivars of several species are known for their variegated leaves (e.g. T. cerinthoides, T. decora, T. fluminensis and T. mundula; Fig. 4), but also found in members of different subgenera [e.g. T. spathacea Sw., T. zanonia (L.) Sw. and T. zebrina -T. subg. Campelia -, T. pallida (Rose) D.R.Hunt and T. sillamontana Matuda -T. subg. Setcreasea -, but it is unknown to me to occur in T. subg. Mandonia and T. subg. Tradescantia; pers. observ.]. However, this variegation does not seem to be homologous to the silver stripes commonly observed in other members of the family. These stripes do not seem to be produced by the concentration of aerenchymatous tissue, but actually seem to be caused by the loss of pigmentation in the leaves. They actually look similar to the symptoms caused by some strains of the tulip breaking virus (family Potyviridae) in the perianth of Liliales (McKay and Warner 1933;McWhorter 1938) and more precisely to symptoms caused the commelina yellow mottle virus (Badnavirus spp., family Caulimoviridae), being generally malefic to the infected plants (Hull 2007;Valverde et al. 2012). These white stripes (sometimes also yellow or pink to vinaceous, due to the presence of secondary pigments; Fig. 4) are not commonly observed in natural populations, being almost exclusively recorded in cultivated plants (pers. observ.). During cultivation in the greenhouses of the Jardim Botânico do Rio de Janeiro, some specimens not originally striped, were observed to acquire such features. The appearance of white to yellow stripes in the leaves occurred shortly after a great aphid and mealybug infestation struck the live collection. Specimens from different genera, such as Commelina and Floscopa also acquired such stripes. After some months, the affected specimens either withered and died or survived and lost the stripes (pers. observ.). This pattern is coherent with the one observed in the transmission and spread of viruses from families Potyviridae,  Caulimoviridae and other plant infecting families that cause mosaic and breaking patterns in plants ( McKay and Warner 1933;McWhorter 1938;Andret-Link and Fuchs 2005;Hull 2007;Valverde et al. 2012). Thus, in the present study, striped specimens of T. subg. Austrotradescantia are disregarded, being considered merely as sick plants or artificially selected morphotypes of no taxonomic relevance.
Inflorescences. The inflorescence architecture in T. subg. Austrotradescantia follows the double-cincinni pattern, as described by Panigo et al. (2011) and indicated by Pellegrini (2017) as characteristic to Callisia s.l., Tradescantia and Tripogandra s.l. The cincinni bracts are always frondose, being leaf-like in most species but spathaceous in T. decora and T. umbraculifera (Fig. 5C, D, I). The base of the cincinni bracts can be saccate or not, with saccate bracts being synapomorphic to the T. fluminensis group (Pellegrini 2017). Supernumerary bracts are rare in T. subg. Austrotradescantia, being exclusively recorded for T. decora. The cincinni are always sessile, contracted and fused back to back. Due to great reduction in the main florescence, the cincinni seem opposite in most specimens. Nonetheless, in some specimens, a malformation in the inflorescence can cause the internodes between the cincinni to elongate, thus producing subopposite cincinni (Fig. 5A;Pellegrini 2017). Most inflorescences are composed of two cincinni, as the double-cincinni architecture would suggest. Nonetheless, some exceptions are recorded, with T. crassula producing perfect double-cincinni, but also commonly producing axillary inflorescences composed of a solitary cincinnus ( Fig. 5B; Pellegrini 2017). Furthermore, T. decora is the only species in T. subg. Austrotradescantia to regularly present main florescences with more than two cincinni, generally producing main florescences with 2-3(-5) cincinni (Fig. 5C, D;Pellegrini 2017).
Flowers. The flowers in T. subg. Austrotradescantia are always flat (i.e. not forming a floral tube), with flowers being held in an upright position at pre-anthesis and anthesis and later acquiring a deflexed position at post-anthesis and fruiting (Fig. 6F;Pellegrini 2017). As with the other species of Tradescantia, the species of T. subg. Austrotradescantia possess scentless flowers (Pellegrini 2017) and, like all species of Commelinaceae, completely lack nectaries of all kinds (Faden 1992). A marking floral conservatism can be easily observed in T. subg. Austrotradescantia, with gross floral morphology presenting little taxonomic relevance for species delimitation in the subgenus (Pellegrini 2017). Some taxonomic relevance can be given to the shape of the floral buds (that can be of great help in differentiating closely related taxa) and floral diameter (which can also help differentiate some species).
Sepals. Aside from the pubescence, little variation is observed in the sepals of T. subg. Austrotradescantia. The sepals are always equal, free, chartaceous, ovate, with acute apex. They can range from medium to dark green or from purple to vinaceous to dark vinaceous and can be dorsally keeled or not (Fig. 6A-C;Pellegrini 2017). Measures can be of some help, but they do commonly overlap between closely related species.
Petals. The deliquescent petals are also quite homogeneous in T. subg. Austrotradescantia, being always sessile (i.e. without a claw, like some species of T. subg. Campelia, T. subg. Mandonia and T. subg. Setcreasea and all species of T. subg. Tradescantia; Pellegrini 2017), equal, free, elliptic to ovate to broadly ovate, with cuneate to obtuse base, glabrous margin and acute apex. Little colour variation is observed, especially when compared with T. subg. Campelia and T. subg. Tradescantia. All Androecium. As shown by Pellegrini (2017), all species of T. subg. Austrotradescantia possess filaments densely bearded at the base with moniliform hairs, these hairs being as long as the stamens or at least the filaments; anthers basifixed, with expanded, rhomboid and yellow connectives, divergent and elliptic anther sacs and yellow pollen grains in vivo (Fig. 6F). This pattern is exclusive to T. subg. Austrotradescantia (Pellegrini 2017), but of almost no relevance in differentiating the species within the subgenus.
Gynoecium. The gynoecium in T. subg. Austrotradescantia presents a highly conservative morphology, being always white and glabrous, the ovary ranging from subglobose to globose, the locules 2-ovulate, ovules anatropous with axial placentation, the style being always straight at anthesis and post-anthesis, obconical at base, conical at the apex and culminating in a reduced and punctate stigma (Pellegrini 2017). Finally, the pistil, as a whole, can either be much longer than or approximately the same length as the stamens.
Capsules and seeds. Fruit morphology is extremely conservative in Tradescantia, being characterised by light to medium brown, thin-walled, loculicidal capsules, subglobose to globose in shape, externally glabrous and smooth and sometimes apiculate due to the persistent base of the style. The capsules are always 3-valved (Fig. 7A), with the only known exception in the genus being T. orchidophylla Rose & Hemsl., which seems to exclusively present a 2-locular gynoecium and, consequently, producing 2-valved capsules. Each locule can produce up to two seeds, which will directly influence their shape. The seeds range from ellipsoid to narrowly trigonal, commonly with a more truncate side if two seeds are produced in the same locule, ventrally flattened, cleft or not towards the embryotega (with cleft seeds being synapomorphic to the T. crassula group; Fig. 7B) and the testa can be either costate (Fig. 7B, C) or rugose, with ridges or pits radiating from the embryotega (i.e. rugose testa being exclusive to the T. tenella species complex; Fig. 7D). The embryotega is dorsal and relatively inconspicuous, without a prominent apicule, being generally covered by a cream farinae ( Fig. 7B-D). The hilum is linear, located on a mild ridge and can vary in length depending on the species group: (1) longer than ½ the length the seed in the T. crassula group (  Diagnosis. Similar to T. tenella due to its definite base, erect and densely branched stems, involute ptyxis, leaf-blades with conspicuous secondary veins, saccate and strongly unequal cincinni bracts, keeled sepals, pistil the same length as the stamens, seeds with rugose testa and hilum shorter than ½ the length of the seed. It can be differentiated by its fibrous stems, sessile leaves with velutine to hispid, light brown to hyaline indumentum, broadly ovoid floral buds, sepals with a mixture of glandular and eglandular hairs restricted to the keel and petals always white and plicate. Description. Herbs ca. 10-35 cm tall, with a definite base, terrestrial. Stems erect, fibrous, branched to densely branched; internodes 1.8-6.1 cm long at base, distally shorter, dark green to vinaceous, glabrous, except for a leaf-opposed longitudinal line of short, uniseriate, light brown to hyaline hairs. Leaves distichously-alternate, sessile; ptyxis involute; sheaths 4.1-7.6 mm long, light green to pink with dark green to purple striations, glabrous, margin setose, hairs light brown to hyaline; blades 3.3-10.2 × 0.9-3.4 cm, elliptic to ovate, flat, membranous to chartaceous, velutine to hispid on both sides, rarely hairs restricted to the midvein, hairs light brown to hyaline, adaxially dark green, abaxially green, sometimes with vinaceous blotches, turning dark brown to olive-green on both sides when dry, base obtuse to rounded, margin ciliolate, slightly revolute, apex acute to acuminate; midvein conspicuous, adaxially impressed, secondary veins conspicuous, adaxially impressed, abaxially prominent, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 1.9-3.7 cm long, dark green to vinaceous, glabrous, except for a leaf-opposed longitudinal line of short, uniseriate, light brown to hyaline hairs; basal bract inconspicuous, tubular, hyaline, glabrous; peduncle bracts absent; supernumerary bracts absent; cincinni bracts 1.2-3.4 × 0.4-1.3 cm, leaf-like, unequal to strongly unequal to each other, elliptic to narrowly ovate to ovate, velutine to hispid on both sides, rarely hairs restricted to the midvein, hairs light brown to hyaline, adaxially dark green, abaxially green with vinaceous blotches, base cordate to round, saccate, margin ciliolate, slightly revolute, apex acuminate; double-cincinni (4-)6-8-flowered; bracteoles inconspicuous, imbricate, linear-triangular to triangular, hyaline. Flowers 1.1-1.3 cm diam.; floral buds broadly ovoid, apex acute; pedicels 1.2-3.4 mm long, upright at anthesis and preanthesis, reflexed at post-anthesis, vinaceous, densely glandular-pubescent, rarely with a mixture of glandular and eglandular, hyaline hairs; sepals 3.8-5.3 × 2.6-4.2 mm, dorsally keeled, with a mixture of glandular and eglandular, hyaline hairs restricted to the keel, hairs hyaline to light brown; petals 6.6-8.2 × 3.7-5.2 mm, plicate, white; filaments 3.6-4.9 mm long, anthers 0.4-0.6 × 0.5-0.6 mm; ovary 0.9-1.1 × 0.8-1.2  Distribution and habitat. Tradescantia atlantica is endemic to Brazil, more precisely to the states of Minas Gerais, Rio de Janeiro and São Paulo; in the Atlantic Forest domain (Fig. 9). It can be found growing as a terrestrial understorey in shaded and moist forests.
Phenology. It was found in bloom and fruit from October to June but peaking during January.
Etymology. The epithet makes reference to this species' distribution range, restricted to the Atlantic Forest domain.
Conservation status. Tradescantia atlantica possesses a wide EOO (ca. 60,715.793 km 2 ), but a considerably narrow AOO (ca. 32.000 km 2 ). Since it is only known from seven very fragmented collections, following the IUCN (2001) Comments. Tradescantia atlantica is a member of the T. tenella species complex, being morphologically similar to T. tenella and T. tucumanensis, due to its definite base, conspicuous secondary veins ( Fig. 8B), saccate and unequal to strongly unequal cincinni bracts (Fig. 8F), keeled sepals ( Fig. 8G), pistil the same length as the stamens (Fig. 8H), seeds with rugose testa and hilum shorter than ½ the length of the seed (Fig. 8I). It was previously tentatively included by me (Pellegrini 2015) under a much broader T. tenella, due to its erect stems and ovoid floral buds. Nonetheless, after further herbarium and field studies, I have come to the conclusion it indeed merits taxonomic recognition. The fibrous stems and sessile leaves ( Fig. 8B) vegetatively differentiate T. atlantica from T. tenella, with the fibrous stems being unique in the subgenus. Also, the velutine to hispid indumentum covering the leaves ( Tradescantia atlantica can also be differentiated from the new T. tucumanensis by its fibrous stems (vs. succulent in T. tucumanensis), sessile leaves with velutine to hispid indumentum (vs. at least the basal ones subpetiolate, sparsely hirsute to hirsute), broadly ovoid floral buds (vs. ellipsoid), sepals with a mixture of glandular and eglandular hairs restricted to the keel (vs. with a mixture of glandular and eglandular hairs, but exclusively hispid along the keel in T. tucumanensis) and petals always white and plicate (vs. ranging from white to pink and flat). Description. Herbs ca. 10-60 cm tall, with a definite base, terrestrial or rupicolous, rarely epiphytes. Stems erect, succulent, little branched, branching at the base, rarely branching at the upper half; internodes 1-7.4 cm long at base, distally shorter, green with vertical reddish-purple striations to vinaceous, glabrous to velutine to hirsute to glandularpubescent, light-brown to hyaline hairs. Leaves distichously-alternate to spirally-alternate, sessile; ptyxis convolute; sheaths 0.3-1.3 cm long, green to pink to vinaceous, glabrous or velutine to hispid, margins densely setose to hispid, hairs hyaline to light brown to golden, sometimes also with some glandular hairs; blades 1.5-17.5 × 0.6-3 cm, elliptic to broadly elliptic to ovate to broadly ovate to obovate to broadly obovate, falcate to complicate, succulent, velutine to hispid on both sides or adaxially glabrous to sparsely hispid, abaxially hispid, hairs hyaline to light brown to golden, commonly also with a mixture of glandular hairs, adaxially light to medium to dark green, sometimes with vinaceous stripes, abaxially green to vinaceous, turning olive-green to brown when dry, base cordate to obtuse, rarely cuneate, margin green to vinaceous, ciliolate to ciliate, slightly revolute, apex acute to obtuse; midvein conspicuous, adaxially impressed, secondary veins conspicuous, adaxially slightly impressed, abaxially slightly impressed, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 0.4-5.5 cm long, green to vinaceous, glabrous to velutine to hispid, hairs hyaline to light brown to golden, commonly also with a mixture of glandular hairs; peduncle bracts absent; supernumerary bracts absent; cincinni bracts 0.8-5.1 × 0.5-2.1 cm, leaf-like, similar to each other, broadly elliptic to ovate to broadly ovate, velutine to hispid on both sides or adaxially glabrous to sparsely hispid, abaxially hispid, hairs hyaline to light brown to golden, adaxially light to medium to dark green, rarely with vinaceous stripes, abaxially green to vinaceous, base cordate to obtuse, not saccate, margin ciliolate to ciliate, slightly revolute, apex acute to obtuse; double cincinni 6-22-flowered. Flowers 1.3-1.6 cm diam., pedicels 0.5-2 cm long, green to vinaceous, velutine to hispid, hairs hyaline to light brown, commonly also with a mixture of glandular hairs; floral buds ovoid; sepals 5-7.8 × 2.2-3.4 mm, not keeled, green to vinaceous, velutine to hispid, commonly also with a mixture of glandular hairs, hairs hyaline to light brown, rarely golden; petals 4.9-7.8 × 4.4-7.2 mm, flat, white or white with pink apex to light pink to pink to lilac; filaments 4.7-6.7 mm long, anthers 0.8-1 × 1-1.4 mm; ovary 1-1.5 × 0.9-1.5 cm, style 2.9-5.7 cm long; pistil longer than the stamens. Capsules 3.5-4.5 × 2.3-3.6 cm. Seeds 1.2-2.2 × 0.9-1.7 mm, testa medium to dark grey, cleft towards the embryotega, costate; hilum longer than ½ the length of the seed.   Distribution and habitat. Tradescantia cerinthoides is known to occur in Argentina, Brazil (states of Minas Gerais, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul) and Uruguay; in the Atlantic Forest, Cerrado, Chaco and Pampa domains (Fig. 11). It can be found in grasslands growing in full sun or in shaded conditions, directly over rock or as a terrestrial plant. It can be also found growing in sand dunes and in restinga formations in Southern Brazil.

Tradescantia cerinthoides
Phenology. It was found in bloom and fruit throughout the year but peaking during the rainy season and being less commonly found in bloom during the dry season.
Etymology. The epithet "cerinthoides" means "similar to pollen grains", probablymaking reference to the moniliform hairs of the filaments. These hairs are theorised by Faden (1992) to simulate pollen grains and deceive pollinators into visiting the flowers of Commelinaceae.
Conservation status. Tradescantia cerinthoides possesses a wide EOO (ca. 945,153.803 km 2 ), being widely cultivated worldwide as an ornamental plant and being potentially an invasive species in the same regions as T. fluminensis. In its natural habitats, T. cerinthoides forms dense subpopulations, reproducing either by clones or sexually by seeds. Thus, following the IUCN recommendations (IUCN 2001), T. cerinthoides should be considered Least Concern (LC).
Nomenclatural notes. Tradescantia blossfeldiana was described by Mildbraed (1940) based on cultivated material by H. Blossfeld at the Botanischer Garten und Botanisches Museum Berlin-Dahlem (Germany), and originally collected in Argentina. Mildbraed gives a detailed description that gives me no doubt that this species should be treated as a synonym of T. cerinthoides, as proposed by Hunt (2001). Nonetheless, Mildbraed (1940) cites no examined material. It is known that Mildbraed worked in Berlin (Stafleu and Cowan 1981), however no specimen matching the protologue was ever found at B. Stearn (1955) published a beautiful watercolour for T. blossfeldiana, together with horticultural comments for this species in Curtis's Botanical Magazine. According to Stearn (1955), the watercolour presented by him was based on the living specimen, still in cultivation at the time at the Botanischer Garten und Botanisches Museum Berlin-Dahlem, which served as the base for Mildbraed's description. Cuttings from the original specimens at the Botanischer Garten und Botanisches Museum Berlin-Dahlem were then sent to the Royal Botanical Gardens, Kew, by Dr. William Curtis on 1931. The plants flowered several times and vouchers were done in 1931, 1939, 1940, and 1951 and placed at K. After careful study of these voucher specimens at K, I have chosen the specimens collected in 1951, since one of the sheets is clearly the one on which the watercolour, published by Stearn (1955), was based. Thus, specimen K000501910 is here designated as the neotype of T. blossefeldiana, while specimen K000501909 is treated as the isoneotype.
Comments. Tradescantia cerinthoides is a member of the T. crassula group, due to its erect stems (Fig. 10A), definite base (Fig, 10B), convolute ptyxis (Fig, 10B), complicate and/or falcate leaves (Fig. 10B, C), cincinni bracts not saccate at base (Fig. 10K), petals that range from white to pink to lilac (Fig. 10N), pistil longer than the stamens (Fig.  10N), seed cleft towards the embryotega and hilum longer than ½ the length of the seeds (Fig. 10) (Pellegrini 2015(Pellegrini , 2016(Pellegrini , 2017. It can be easily differentiated from the remaining species of this group by a combination of: sepals not keeled and evenly pubescent (with indumentum ranging from velutine to hispid and generally with a mixture of glandular and eglandular hairs; Fig. 10L, M). It is highly polymorphic, being together with T. crassula, the only two species in the subgenus where the phyllotaxy has been observed to vary in adult specimens. The individuals presenting spirally-alternate leaves with shortened internodes (i.e. producing rosette leaves) and white petals represent the morphological variation described by Seubert (1855) as T. koernickeana. Also, its leaves are generally densely covered by indumentum on the abaxial side, but some individuals with completely glabrous leaves can also be found. On the other hand, the specimens with spirally-alternate leaves and elongated internodes represent T. cerinthoides as originally described by Kunth (1843). Finally, the specimens with distichously-alternate leaves, with blades generally adaxially green with vinaceous stripes, glabrous or sparsely pubescent, abaxially vinaceous and densely pubescent and petals ranging from pink to lilac, represent the morphological variation described by Mildbraed (1940) as T. blossfeldiana. Nonetheless, T. cerinthoides shows great morphological variation in the same subpopulation. The same subpopulation can present individuals from all three aforementioned morphotypes growing together and, more importantly, with all kinds of intermediate forms between them (Fig.  10N). The same wide morphological variation was also observed in cultivation, with all morphs crossing and producing viable seeds (pers. observ.). Some of the morphological variation observed in T. cerinthoides can be partially explained by environmental features (e.g. plant stature and growth form, overall plant succulence, leaf shape and colouration etc.). Nonetheless, most of the obviously observed morphological variation seems to have at least a partial genetic background, with characters such as indumentum of the vegetative organs and colouration of the petals being maintained regardless of the environment. This still poorly understood variation seems to be the main cause of the description for all of its species synonyms and also as a cause for this species being so popular in cultivation. In this scenario, it seems illogical to accept several ill-defined species based on non-clearcut character states, instead of the broader T. cerinthoides as proposed by Hunt (1980Hunt ( , 2001. Populational studies, coupled with reproductive and morphometrical studies, are needed to help us better understand this species' morphological plasticity. Tradescantia cerinthoides is the most popular species from the T. crassula group, as a potted plant. This is especially due to the beautiful pink to lilac flowers that are common in the cultivated specimens and its generally dense leave indumentum. Description. Herbs ca. 10-40 cm tall, with an indefinite base, terrestrial or rupicolous, rarely epiphytes. Stems prostrate with ascending apex, delicate to slightly succulent, little to densely branched; internodes 1.5-8.2 cm long at base, distally shorter, medium to dark green or vinaceous, velutine to hispid, hairs golden to light brown. Leaves distichously-alternate, sessile; ptyxis involute; sheaths 0.4-1 cm long, light to medium green to vinaceous, sometimes with green striations, velutine to hirsute, margin densely setose, hairs golden; blades 1.8-7.6 × 0.9-3.4 cm, elliptic to broadly elliptic or lanceolate to ovate to broadly ovate, flat, succulent, velutine to hispid on both sides, hairs golden to light brown, adaxially medium to dark green, abaxially light to medium green or vinaceous, turning black to dark brown or olive-green when dry, base cordate to obtuse, margin ciliolate, slightly revolute, apex acute, sometimes acuminate; midvein conspicuous, adaxially impressed, secondary veins inconspicuous, adaxially inconspicuous, abaxially inconspicuous, becoming more evident abaxially when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles (0.4-)1.1-9.5 cm long, velutine to hispid, hairs golden to light brown; cincinni bracts 0.9-6.6 × 0.3-3.1 cm, unequal to strongly unequal to each other, elliptic to ovate to broadly ovate, leaf-like, velutine to hispid, hairs golden to light brown, medium to dark green, abaxially light to medium green or vinaceous, base cordate to obtuse, saccate, margin ciliolate, slightly revolute, apex acute; double cincinni (4-)6-20-flowered. Flowers 1.1-1.6 cm diam., pedicels 0.6-1.3 cm long, glandular-pubescent; floral buds broadly ovoid; sepals 4.7-6 × 2.2-4 mm, not keeled, light to medium green, glandular-pubescent or with a mixture of glandular and eglandular, golden to light brown hairs; petals 7.2-9 × 4.6-6.2 mm, white; filaments 5.4-6.2 mm long, anthers 0.6-1 × 0.3-0.7 mm; ovary 0.8-1.7 × 0.7-1.4 mm, style 3.8-4.6 cm long; pistil the same length as the stamens. Capsules 2.7-3.2 × 2.2-2.8 mm. Seeds 1.1-1.5 × 1.0-1.4 mm, testa grey to greyish-brown, not cleft towards the embryotega, costate; hilum ½ the length of the seed.

Distribution and habitat.
Tradescantia chrysophylla is endemic to Brazil, more precisely to the states of Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul; in the Atlantic Forest domain (Fig. 13). It can be found growing as a terrestrial, rupicolous or as an epiphyte understorey in shaded and moist forests.
Phenology. It was found in bloom and fruit from July to December but peaking during October.
Etymology. The epithet "chrysophylla" means "golden leaves" and is given after the golden hairs that cover the whole plant, but especially the leaves.
Conservation status. According to Pellegrini et al. (2017), T. chrysophylla possesses a wide EOO (here updated to ca. 234,968.601 km 2 ), but a considerably narrow AOO (ca. 60.000 km 2 ). It is known from very few and fragmented collections and, following the IUCN (2001) recommendations, it should be considered as Endangered [EN, A2cde+B2ab(ii, iii, iv)+D2].
Comments. Tradescantia chrysophylla is morphologically similar to T. cymbispatha, T. fluminensis and T. mundula due to their indefinite base (Fig. 12, B), prostrate stems with ascending apex (Fig. 12A, B), involute ptyxis, saccate cincinni bracts, white petals (Fig. 12H, I), pistil as long as the stamens, seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 12J). However, it can be easily differentiated from T. fluminensis and T. mundula by its sessile succulent leaves, blades evenly covered by indumentum and inconspicuous secondary veins (vs. leaves membranous, blades glabrous or unevenly covered by indumentum and impressed secondary veins), floral buds broadly ovoid (vs. narrowly ovoid to ovoid) and sepals without keels (vs. keeled sepals). Tradescantia chrysophylla is considerably more similar to T. cymbispatha due to their sessile, succulent leaves evenly covered by indumentum, inconspicuous secondary veins and sepals without keels. Nonetheless, in T. chrysophylla, the indumentum is velutine to hispid and golden to light brown but sometimes becoming light-brown when over-exposed to the sun (vs. strigose and hyaline in T. cymbispatha), the cincinni bracts are unequal to strongly unequal (vs. equal) and the pedicels and sepals are glandular-pubescent with golden to light brown hairs or covered by a mixture of glandular and eglandular hairs (vs. velutine, covered exclusively by eglandular hyaline hairs). Furthermore, T. chrysophylla can be differentiated from almost all the species of T. subg. Austrotradescantia by its golden to light brown indumentum covering almost the entire plant. The only other species known to possess a similarly coloured indumentum are T. cerinthoides (T. crassula group; Pellegrini 2015Pellegrini , 2016 and T. tucumanensis (T. tenella species complex; Pellegrini 2017). Tradescantia chrysophylla can be easily differentiated by its indefinite habit base (vs. definite in T. cerinthoides), prostrate stems (vs. ascending to erect), saccate cincinni bracts (vs. non-saccate), pistil the same length as the stamens (vs. longer than the stamens), petals always white (vs. ranging from white to pink to lilac), seed not cleft towards the embryotega (vs. cleft) and hilum ½ the length of the seed (vs. longer than ½ the length). Tradescantia chrysophylla and T. tucumanensis can be confused due to their similar habit, light brown to golden indumentum and asymmetrical cincinni bracts. Nonetheless, both species are easily differentiated by their non-overlapping distributions (endemic to Brazil in T. chrysophylla vs. restricted to the Tucumano-Boliviano Forest in T. tucumanensis), leaf morphology (leaves sessile, succulent, with inconspicuous secondary veins in T. chrysophylla vs. subpetiolate, membranous to chartaceous, with impressed secondary veins in T. tucumanensis). Finally, T. chrysophylla is easily identified in dried specimens, since it becomes peculiarly dark brown to black, added to the large epidermal domes in the leaf-blades. Hassemer et al. (2017) describe T. serrana as a new species, known from a sole collection and endemic to the state of Santa Catarina. They compare their new species with T. umbraculifera, with which it bears very little resemblance. They also compare T. serrana with T. chrysophylla, differing both species based on the shape of their leaves, concentration of hairs on both sides of the blades, the presence of dorsal keels in the sepals, the posture of the petals (i.e. flat vs. plicate) and the relative length between the androecium and the pistil. Nonetheless, the sepals' midvein was misinterpreted by the authors as representing dorsal keels (which, for instance, can be easily observed in T. fluminensis; Fig. 6B), the repandous petals as being plicate (which is only known to occur in T. atlantica and T. fluminensis; Fig. 6D-F), but they failed to realise that the relative length between the stamens and pistil used by me in my MSc thesis (Pellegrini 2015), is actually approximate and that in the T. crassula group, the pistil is considerably longer than the stamens, as opposed to the approximately equal length in the T. fluminensis group. Tradescantia chrysophylla and T. serrana share the sessile and succulent leaves with inconspicuous secondary veins, blades velutine to hispid with light brown to golden hairs, unequal to strongly unequal cincinni bracts and pedicels and sepals glandular-pubescent or with a mixture of glandular and eglandular hairs. Tradescantia serrana undoubtedly represents nothing more than a synonym of T. chrysophylla and ishere treated as such. 3) cm long, green, the axillary ones sessile, glabrous, sometimes with a leaf-opposed longitudinal line of short, uniseriate, light brown to hyaline hairs; peduncle bracts absent; supernumerary bracts absent; cincinni bracts 1.2-3.9(-6) × 0.7-2.1 cm, leaflike, rarely unequal or reduced in some axillary inflorescences, broadly ovate to ovate, leaf-like, glabrous, adaxially light to medium to dark green, abaxially light to medium green, base cordate to obtuse, not saccate, margin glabrous to minutely ciliolate, sparsely setose at base, slightly revolute, apex acute; main florescence 8-28-flowered. Flowers 0.8-1.2 cm diam., pedicels 0.7-1.5 cm long, green to vinaceous, glabrous, rarely sparsely glandular-pubescent; floral buds broadly ovoid; sepals 4.6-7.5 × 2.7-4.4 mm, dorsally keeled, green, rarely vinaceous, setose, with long hyaline hairs along the keel; petals 6-7.3 × 4.7-5.2 mm, flat, white; filaments 5.1-6.6 mm long, anthers 0.6-0.8 × 1.1-1.3 mm; ovary 1.7-1.9 × 1.5-1.7 cm, style 4.2-5 cm long; pistil longer than the stamens. Capsules 3.6-4.2 × 2.1-2.7 mm. Seeds 1.2-1.8 × 1.1-1.6 mm, testa grey to greyish-brown, cleft towards the embryotega, costate; hilum longer than ½ the length of the seed.   Comments. Tradescantia crassula is very plastic in plant stature, leaf shape and flower size. Few vegetative characters were observed to be constant in the T. crassula group and thus are of little taxonomic relevance. Nonetheless, all studied individuals of T. crassula always present glabrous leaves (Fig. 14G), sepals with long hairs along the keel (Fig. 14H-J) and white petals (Fig. 14J). Added to that, most of the known variation can be related to ecological conditions. Furthermore, species in this subgenus are morphologically variable and, when kept in cultivation or growing in shaded areas, they can change their vegetative morphology quite drastically, changing between the different morphs (more or less succulent plants, smaller or taller plants, plants with different leaf shapes). Thus, I agree with Pellegrini et al. (2017) in treating T. schwirkowskiana as a mere synonym of T. crassula. Detailed comments on the morphological similarities between T. crassula and closely related species and the species morphological variation are presented by Pellegrini et al. (2017), while Pellegrini (2017) discusses its systematic affinities. Description. Herbs ca. 5-30 cm tall, with an indefinite base, terrestrial, rupicolous or epiphytes. Stems prostrate with ascending apex, delicate to slightly succulent, little to densely branched; internodes 0.8-6.4 cm long at base, distally shorter, medium to dark green or reddish-purple to vinaceous, strigose, hairs hyaline. Leaves distichously-alternate, sessile; ptyxis involute; sheaths 0.4-0.7 cm long, green to green with vinaceous striations or vinaceous, strigose, margin setose, hairs light brown; blades elliptic to broadly elliptic or broadly ovate, 1.2-4.6 × 0.6-2.2 cm, flat, succulent, strigose on both sides, adaxially dark to medium bluish-green, turning olive-green to medium brown when dry, abaxially light to medium green or vinaceous, turning tan to light brown when dry, base cordate to obtuse, margin green to vinaceous, ciliolate, slightly revolute, apex acute; midvein conspicuous, adaxially impressed, secondary veins inconspicuous, adaxially inconspicuous, abaxially inconspicuous, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 0.6-4.3 cm long, medium to dark green or reddish-purple to vinaceous, strigose; cincinni bracts similar to each other, broadly elliptic to broadly ovate, 1-3.5 × 0.6-1.6 cm, leaf-like, strigose on both sides, adaxially dark to medium bluish-green, abaxially light to medium green or vinaceous, base cordate, saccate, margin ciliolate, slightly revolute, apex acute; double cincinni 6-10-flowered. Flowers 0.9-1.5 cm diam., pedicels 0.9-1.6 cm long, vinaceous, velutine, sometimes with some odd glandular hairs, hairs hyaline; floral buds broadly ovoid; sepals 6-6.5 × 2-2.6 mm, without keels, vinaceous, rarely green, velutine, hairs hyaline; petals 0.5-0.7 × 0.3-0.5 cm, flat, white, sometimes pink to lilac; filaments 4.1-4.6 mm long, anthers 0.8-1 × 1-1.3 mm; ovary 0.9-1.2 × 0.6-1 cm, style 2.6-3.2 cm long; pistil the same length as the stamens. Capsules 2.9-3.8 × 1.8-2.2 mm. Seeds 1.4-1.8 × 1.1-1.5 mm, testa grey to greyish-brown, not cleft towards the embryotega, costate; hilum ½ the length of the seed.    (Fig. 17). It can be found growing understorey in shaded and moist forests as terrestrial, rupicolous and sometimes as an epiphyte.

Tradescantia cymbispatha C.B.Clarke in De
Phenology. It was found in bloom throughout the year but peaking during the rainy season and being less commonly in bloom during the dry season. Fruit has been sporadically observed during the flowering period.
Etymology. The epithet makes clear the great nomenclatural confusion created by Clarke's misinterpretation of Vellozo's plate. It means "boat-shaped bract", a character present only in the Bolivian T. praetermissa M.Pell. and other members of T. subg. Campelia, on which Clarke partially based his description Pellegrini 2017).
Conservation status. Tradescantia cymbispatha possesses a wide EOO (ca. 1,201,901.629 km 2 ), being also cultivated throughout its distribution range as an ornamental plant. Thus, following the IUCN recommendations (IUCN 2001), it should be considered Least Concern (LC).
Nomenclatural notes. Tradescantia cymbispatha was originally described as T. geniculata Vell. on Florae fluminensis (Vellozo 1829, 1831). However, since this name was a posterior homonym of T. geniculata Jacq., it was almost completely overlooked by most botanists until Clarke (1881) inadvertently proposed T. cymbispatha C.B.Clarke as a replacement name. These matters were only recently clarified by Pellegrini et al. (2015Pellegrini et al. ( , 2016. Comments. Tradescantia cymbispatha is morphologically similar to T. chrysophylla, T. fluminensis and T. mundula due to their indefinite base, prostrate stems with ascending apex (Fig. 16A, B), involute ptyxis, saccate cincinni bracts (Fig. 16B), white petals (Fig. 16F), pistil as long as the stamens (Fig. 16B, E, F), seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 16G). It can be easily differentiated from T. fluminensis and T. mundula by its sessile leaves with inconspicuous secondary veins (vs. subpetiolate with impressed secondary veins, in T. fluminensis and T. mundula), blades evenly covered by indumentum (vs. glabrous or unevenly covered by indumentum) and sepals without dorsal keels (vs. sepals dorsally keeled). Tradescantia cymbispatha is morphologically more closely related to T. chrysophylla due to their sessile and succulent leaves with inconspicuous secondary veins, blades abaxially vinaceous and sepals without dorsal keels. Both species can be differentiated based on pubescence of the vegetative and reproductive organs (leaves strigose, pedicels and sepals velutine, hairs hyaline in T. cymbispatha vs. leaves velutine to hispid, pedicels and sepals glandular-pubescent or with a mixture of glandular and eglandular hairs, hairs light brown to golden), symmetry of the cincinni bracts (equal in T. cymbispatha vs. unequal in T. chrysophylla) and petal colour (white but sometimes pink or lilac in T. cymbispatha vs. always white in T. chrysophylla). In the field, T. cymbispatha is a very distinctive species, being easily differentiated from the remaining species of the T. fluminensis group by its adaxially dark to medium bluish-green and abaxially vinaceous leaves, which possess a peculiar velvety glow due to its dense strigose hyaline hairs. The stems are prostrate, forming dense mats that may cover large areas and producing a bluish herbaceous understorey formation. Furthermore, T. cymbispatha possesses some very interesting characters that become evident when specimens are dried. Firstly, the intense bluish-green pigmentation of the adaxial side becomes olive-green to medium brown, while the vinaceous pigmentation (i.e. anthocyanin) evaporates, leaving the abaxial side tan to light brown. Also, despite possessing inconspicuous secondary veins due to its succulent leaves, dried leaves of T. cymbispatha acquire a striate aspect, due to the large and linearly arranged epidermal domes possessed by this species.   Flowers 1-1.5 cm diam.; floral buds broadly ellipsoid, apex acuminate; pedicels 0.7-2 cm long, green, glabrous, rarely sparsely glandular-pubescent, if present hairs hyaline; sepals 4.8-7.3 × 1.5-3 mm, green, without dorsal keels, glabrous, rarely sparsely pilose at the apex, when present hairs eglandular, hyaline; petals 4-8.6 × 2.7-5.4 mm, flat, white to white with pink apex to light pink; stamens with filaments 2.8-5 mm long, anthers 0.8-1 × 1-1.2 mm; ovary 1-1.7 × 1-1.3 cm, style 4-5.8 cm long; pistil longer than length the stamens. Capsules 2.8-4.2 × 1.8-3 mm. Seeds 1.1-3 × 1-1.8 mm, cleft towards the embryotega, testa grey to greyish-brown, cleft towards the embryotega, costate; hilum longer than ½ the length of the seed. Distribution and habitat. Tradescantia decora is endemic to the central region of Rio Grande do Sul, Brazil; in the Atlantic Forest and Pampa domains (Fig. 19). It can be found growing as rupicolous, rarely as a terrestrial, in rocky walls.

Tradescantia decora
Phenology. It was found in bloom and fruit in December and April. Etymology. The epithet "decora" means decorated, ornamented, making reference to this species beautiful appearance, decorated by its lush foliage.
Conservation status. Tradescantia decora is only known from five collections restricted to the state of Rio Grande do Sul, one of them cultivated in Berlin and without precise locality. Furthermore, its EOO and AOO are considerably narrow (ca. 672.001 km 2 and ca. 16.000 km 2 , respectively). According to Bünecker et al. (2017), this spe- cies is known to present small subpopulations, with its distribution range being extremely threatened by the construction of small hydroelectric powerplants in the next few years (Marchiori et al. 2014). This might cause most or all known subpopulations to become extinct in the near future, since this species grows in rock walls near water bodies. Thus, in accordance with the IUCN recommendations (IUCN 2001), T. decora should be considered as Critically Endangered [CR,A2ac+B2ab(iii,iv,v Nomenclatural notes. After analysing the original publication (Bull 1892), I have concluded that, like most species described in Seed and Nursery Catalogues, T. decora was probably described based on living and cultivated material. Thus, no voucher was ever made for this name. Unfortunately, Bull (1892) does not present any kind of il-lustration that might be selected as the lectotype for his name. Thus, according to The Code (McNeill et al. 2012, Art. 9.7), I designate the specimen Aona & Machado 958 (UEC barcode UEC057324) as the neotype of T. decora since it is in complete accordance with the protologue.
Comments. After analysing the protologue of T. decora (Bull 1892), it became clear that that this name was conspecific to T. valida and T. multibracteata, due to its erect stems (Fig. 18A), spirally-alternate leaves (Fig. 18A), linear lanceolate to lanceolate leaf-blades with truncate base (Fig. 18A)) and, most importantly, all being restricted to the state of Rio Grande do Sul, Brazil (Fig. 19). Since T. decora has priority over T. valida and T. multibracteata, it should be treated as the accepted name for this species. Tradescantia decora can be easily differentiated from all remaining species of the T. crassula group by the presence of supernumerary bracts, its spathaceous and unequal cincinni bracts, its main florescence being generally composed by 2-3(-5) cincinni (Fig. 18A, E) and sepals not keeled with caducous hairs at the apex (Fig. 18G, H, J). It is similar to T. cerinthoides due to its sepals without dorsal keels (Fig. 18G, H, J). Nonetheless, they can be easily differentiated due to its generally linear elliptic to linear lanceolate to lanceolate leaf-blades (vs. elliptic to broadly elliptic or ovate to broadly ovate or obovate to broadly obovate, in T. cerinthoides), glabrous with margins setose at the base or until the middle (vs. pubescent on both sides or only abaxially, rarely glabrous on both sides and ciliate margins) and pedicels and sepals glabrous or only sparsely pubescent at apex with eglandular hairs (vs. evenly densely velutine to hispid, sometimes with a mixture of glandular and eglandular hairs). Tradescantia decora is much more similar to T. crassula and T. seubertiana, due to their leaf-blades and sepal pubescence. These species can be easily differentiated by the pubescence of the margin of their leaf-sheaths (ciliate to shortly-setose in T. crassula; glabrous in T. seubertiana; and long-setose in T. decora), the pubescence of their sepals (long-setose along the keels in T. crassula; glabrous in T. seubertiana; and glabrous or with few hairs at the apex in T. decora) and by the shape of their floral buds (broadly ovoid T. crassula; ellipsoid in T. seubertiana; and ellipsoid in T. decora).    . When describing T. albovittata, Pynaert (in Burvenich et al. 1885) makes no reference to any herbarium specimen. Nonetheless, the author presents a gorgeous chromolithograph that shows the habit of the plant and its characteristic white-striped leaves. Thus, I designate the original illustration as the lectotype of T. albovittata and reduce it to a synonym of T. fluminensis.

Tradescantia fluminensis
According to Stafleu and Cowan (1986), it is unknown where the specimens of any names described by A. Voss are housed. Voss (in Siebert and Voss 1895), makes no reference to any kind of studied specimen and presents no illustration for most of his names, which prevents the designation of lectotypes. Since no specimens matching the diagnosis of T. fluminensis f. aureovittata were located, I was unable to designate neotypes for it.
Comments. The name T. fluminensis has been misapplied to almost all species of T. subg. Austrotradescantia, even to species from the T. crassula group. Here I consider T. fluminensis as a much lesser variable entity than accepted by previous authors (e.g. Seubert 1871; Clarke 1881; Hunt 1980). Tradescantia fluminensis is morphologically similar to T. cymbispatha, T. chrysophylla, T. hertweckii, T. mundula and T. umbraculifera due to their indefinite base, prostrate stems with ascending apex (Fig. 20A), involute ptyxis, saccate cincinni bracts (Fig. 20D), white petals (Fig. 20D, F), seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 20G). It can be easily differentiated from T. cymbispatha and T. chrysophylla by its subpetiolate leaves with impressed secondary veins (vs. sessile leaves with inconspicuous secondary veins, in T. cymbispatha and T. chrysophylla), blades glabrous or unevenly covered by indumentum (vs. evenly covered by indumentum) and sepals dorsally keeled (vs. sepals without dorsal keels). It is morphologically more closely related to T. hertweckii, T. mundula and T. umbraculifera due to their leaves with impressed secondary veins, dorsally keeled sepals and petals always white. Tradescantia fluminensis can be differentiated from T. mundula due to its glabrous stems (vs. strigose in T. mundula), leaves glabrous (vs. unevenly to evenly strigose), blades membranous to slightly succulent and abaxially light to medium green (vs. chartaceous and abaxially completely to partially vinaceous), sepals pilose with hairs restricted to the keels (vs. evenly velutine) and plicate petals (vs. flat). Tradescantia fluminensis can be differentiated from T. umbraculifera due to its subpetiolate leaves (vs. sessile in T. umbraculifera), leaf-like cincinni bracts (vs. spathaceous), pedicels green at anthesis (vs. white), petals plicate (vs. flat) and pistil as long as the stamens (vs. longer than the stamens). Tradescantia fluminensis is easily identified in the field, due to its emerald green and glossy leaves, that give healthy plants a characteristic plastic aspect.
As aforementioned, T. fluminensis is a popular potted plant, as well as an aggressive weed worldwide. However, many cultivated specimens or weedy populations studied by me actually represent other species from T. subg. Austrotradescantia. In cultivation, many plants are referred to as T. albiflora Kunth, which is here kept as a synonym of T. fluminensis. Nonetheless, they actually represent specimens of T. mundula and, more rarely, specimens of T. cymbispatha and T. crassula. Alternatively, the only other species of T. subg. Austrotradescantia known to me to have been introduced in cultivation is the pink and lilac flowered forms of T. cerinthoides, generally treated by gardeners as T. blossfeldiana. In cultivation, T. fluminensis rarely set seeds and commonly reproduces itself by stem fragmentation. Seed production seems to be also uncommon throughout most of its native range, being only recurrently observed in the state of Rio de Janeiro, Brazil. The reason for this is unknown, since all observed native populations and all specimens kept in cultivation were consistently seen being visited by several insects. My hypothesis is that T. fluminensis actually represents a self-incompatible species and thus some subpopulations are incapable of producing seeds, since they might be exclusively composed of clonal individuals. I believe that, in light of the present taxonomic revision, the reproductive biology of T. subg. Austrotradescantia, especially of the T. fluminensis group, should be properly studied. Diagnosis. Similar to T. fluminensis due to its indefinite base, stems prostrate with ascending apex, involute ptyxis, leaf-blades with conspicuous secondary veins, saccate cincinni bracts, ovoid floral buds, keeled sepals, pistil the same length as the stamens and seeds with costate testa. It can be differentiated by its sessile leaves, blades hispid, margins ciliate, but setose at base, sepals setose along the keel, petals flat and hilum longer than ½ the length of the seed.
Distribution and habitat. Tradescantia hertweckii is endemic to Brazil, more precisely to the state of Rio de Janeiro, municipality of Paraty; in the Atlantic Forest domains (Fig. 23). It can be found growing as a terrestrial, understorey in shaded and moist forests, near river margins.
Phenology. It was found in bloom and fruit in December, during the rainy season.
Etymology. This species is named after Dr. Kate Hertweck, dear colleague and specialist in subtribe Tradescantiinae, in appreciation for her contributions to the systematics and evolution of Monocots and Commelinaceae, especially regarding the evolution of Tradescantia.
Conservation status. Tradescantia hertweckii is known solely from the type collection and, following the IUCN recommendations (IUCN 2001), it should be considered Data Deficient (DD), until further collections and information becomes available.
Comments. Tradescantia hertweckii was considered by me a doubtful specimen related to T. fluminensis and, for this reason, not included in my Master thesis in the initial account for T. subg. Austrotradescantia (at the time T. sect. Austrotradescantia; Pellegrini 2015). It was thought by me to putatively represent a natural hybrid between T. fluminensis and T. umbraculifera, but it differed greatly from the other putative hybrids. Added to that, the inflorescence morphology of T. hertweckii is very similar to the one of T. fluminensis and does not show the very peculiar inflorescence of T. umbraculifera (Fig. 5I). Finally, T. umbraculifera is not known to occur in the same locality as T. hertweckii, with the only other species in the subgenus known to occur in Paraty being T. fluminensis. For these reasons, I have decided to recognise T. hertweckii as a new species, instead of a natural hybrid.
Tradescantia hertweckii is the only species from T. subg. Austrotradescantia not included by Pellegrini (2017) in his morphological phylogeny for the genus. However, it is a member of the T. fluminensis group, due to its indefinite base, stems prostrate with ascending apex, involute ptyxis, leaf-blades with conspicuous secondary veins (Fig. 22A), saccate cincinni bracts (Fig. 22A), pistil the same length as the stamens Fig. 22G) and seeds with costate testa not cleft towards the embryotega (Figs 7C, 22O). It is morphologically similar to T. fluminensis and T. umbraculifera. Tradescantia hertweckii is morphologically similar to T. umbraculifera due to its robust habit, sessile leaves, acuminate to caudate leaf-blades (Fig. 22A) and hilum longer than ½ the length of the seed (Figs 7C, 22O). Nonetheless, it can be easily differentiated from T. umbraculifera by its membranous to slightly fleshy leaf-blades covered by hispid indumentum (vs. chartaceous and glabrous or pilose in T. umbraculifera), 1 inflorescence per leaf axil (vs. 1-4), cincinni bracts leaf-like and unequal to strongly unequal (vs. spathaceous and equal), pedicels green at pre-anthesis and anthesis (vs. white) and pistil as long as the stamens (vs. longer than the stamens). On the other hand, T. hertweckii might be more easily confused with T. fluminensis s.s., due to its glabrous stems (Fig. 22A), membranous to slightly fleshy leaf-blades, 1 inflorescence per leaf axil, leaf-like cincinni bracts (Fig. 22A), sepals with eglandular hairs restricted to the keels (Fig. 22H, N) and pistil as long as the stamens (Fig. 22 G). However, both species can be differentiated based on leaf morphology (leaves sessile, blades hispid, margins ciliate with densely setose base in T. hertweckii vs. subpetiolate, glabrous, evenly ciliolate in T. fluminensis), inflorescence morphology (cincinni bracts unequal to strongly unequal vs. equal), sepal pubescence (setose vs. pilose), petal posture (flat vs. plicate) and hilum relative length (longer than ½ the length of the seed vs. equal).   Voss (in Siebert and Voss 1895) makes no reference to any kind of specimen, presents no illustration for most of his names and no specimens matching the diagnosis of T. fluminensis f. bicolor were located, I was unable to typify it. Comments. Tradescantia mundula is the smallest species from T. subg. Austrotradescantia, being comparable in size only with some specimens of T. tenella. It is morphologically similar to T. cymbispatha and T. fluminensis due to their indefinite base, prostrate stems with ascending apex (Fig. 24A), involute ptyxis, saccate cincinni bracts (Fig. 24F), white petals (Fig. 24F, H), pistil as long as the stamens (Fig. 24G, H), seeds with uncleft testa towards the embryotega and hilum ½ the length of the seed (Fig. 24I). It can be easily differentiated from T. cymbispatha by its subpetiolate leaves with impressed secondary veins (vs. sessile leaves with inconspicuous secondary veins, in T. cymbispatha), blades chartaceous and glabrous or unevenly covered by indumentum (vs. succulent and evenly covered by indumentum) and sepals dorsally keeled (vs. sepals without dorsal keels). It is more easily confused with T. fluminensis, especially in dried specimens, due to their leaves with impressed secondary veins, sepals dorsally keeled and gross floral morphology. Tradescantia mundula can be differentiated from T. fluminensis due to its strigose stems (vs. glabrous in T. fluminensis), leaves unevenly to evenly strigose (vs. glabrous), blades chartaceous and abaxially completely to partially vinaceous (vs. membranous to slightly succulent and abaxially light to medium green), sepals evenly velutine in vivo (vs. pilose with hairs restricted to the keels) and flat petals (vs. plicate). Description. Herbs rupicolous, ca. 20-40 cm tall. Stem erect, succulent, little branched, branching at the base, rarely branching at the upper half; internodes 3.1-6.3 cm long at base, distally shorter, green to reddish-purple to vinaceous, glaucous, glabrous. Leaves distichously-alternate, sessile; ptyxis convolute; sheaths 0.4-1.3 cm long, green to green with vinaceous striations to vinaceous, glaucous, glabrous, margin glabrous; blades ovate to broadly ovate, 2.8-7.7 × 0.9-3.2 cm, falcate to complicate, succulent, glabrous, adaxially light-green, glaucous, abaxially slightly lighter to reddish-purple to vinaceous, glaucous, turning olive-green to light-brown when dry, base cordate to slightly amplexicaulous to obtuse, rarely cuneate, margin green, glabrous, slightly revolute, apex acute; midvein conspicuous to inconspicuous, adaxially impressed to inconspicuous, secondary veins inconspicuous on both sides, becoming more evident on both sides when dry. Inflorescences terminal or axillar in the distal portion of the stems, 1 per leaf axis; peduncles 1.6-3.7 cm long, green to reddish-purple to vinaceous, glaucous, glabrous; cincinni bracts unequal to strongly unequal to each other, ovate to broadly ovate, 0.7-3.3 × 0.4-1.2 cm, leaf-like, glabrous, adaxially lightgreen, glaucous, abaxially slightly lighter to reddish-purple to vinaceous, glaucous, base cordate to obtuse, not saccate, margin glabrous, slightly revolute, apex acute; double cincinni ca. 6-14-flowered. Flowers 0.8-1 cm diam., pedicels 0.7-1.4 cm long, green to reddish-purple to vinaceous, glaucous, glabrous, rarely with some odd glandular hairs; floral buds ellipsoid; sepals 4.8-5.9 × 2.4-4.6 mm, dorsally keeled, green to reddish-purple to vinaceous, glaucous, glabrous; petals 6.3-7 × 3.2-4.4 mm, lightpink to pink; filaments 2.8-3.2 mm long, anthers 0.5-0.8 × 1.3-1.5 mm; ovary 1-1.3 × 0.9-1.2 cm, style 4.3-8.5 cm long; pistil longer than the stamens. Capsule 1.8-2.6 × 1.8-2.2 cm. Seeds 1-1.2 × 0.8-1 mm, testa grey to greyish-brown, costate, cleft towards the embryotega; hilum longer than ½ the length of the seed. cleft towards the embryotega, hilum longer than ½ the length of the seed and for preferentially inhabiting open areas and rocky outcrops. Tradescantia seubertiana is morphologically similar to T. crassula and T. decora, but only superficially similar to T. cerinthoides, especially due to its pink petals (which can range in T. cerinthoides from white to light pink to pink to lilac; Fig. 10N; Pellegrini 2015Pellegrini , 2017Pellegrini et al. 2017). It can be differentiated from T. crassula and T. decora by its glabrous leaf-sheath margin -a very uncommon character in Commelinaceae -(vs. leaf-sheath margin ciliate in T. crassula and long ciliate in T. decora), leaf base cordate to slightly amplexicaulous to obtuse (vs. obtuse to truncate), ellipsoid flower buds (vs. broadly ovoid in T. crassula and T. decora), sepals glabrous (vs. setose along the keel in T. crassula and with minute caducous hairs at the apex of the sepals in T. decora) and by its light pink to pink petals (vs. white in T. crassula). It can be easily differentiated from T. cerinthoides by being almost entirely glabrous (vs. generally densely pubescent in T. cerinthoides with a mixture of glandular and eglandular, hyaline to light brown to golden hairs), inconspicuous secondary veins (vs. conspicuous in T. cerinthoides), its unequal cincinni bracts (vs. equal in T. cerinthoides), ellipsoid floral buds (vs. ovoid in T. cerinthoides) and keeled and glabrous sepals (vs. not keeled and densely pubescent in T. cerinthoides with a mixture of glandular and eglandular, hyaline to light brown to golden hairs). Additionally, T. seubertiana is found growing exclusively on wet rocky cliffs, while T. cerinthoides, T. crassula and T. decora are commonly found growing in open fields, sand dunes near the shore, dry rocky outcrops or understorey as terrestrial or epiphytes.   growing understorey in shaded and moist forests, between rocks near waterfalls and in clay ravines, as terrestrial, rupicolous or epiphyte. Phenology. It was found in bloom and fruit from August to January but peaking during October.

Tradescantia tenella
Etymology. The epithet "tenella" means "delicate", "small", probably making reference to its delicate appearance and also to the small portion available to Kunth when describing the species.
Conservation status. Tradescantia tenella possesses a wide EOO (ca. 791,707.235 km 2 ), and generally forming dense subpopulations. Thus, following the IUCN recommendations (IUCN 2001), it should be considered Least Concern (LC).

Comments.
Tradescantia tenella is one of the most peculiar species from the T. fluminensis clade. It possesses a definite base, erect and succulent stems (Fig. 28A) and flowers that range from white to pink (Fig. 28H, I), which are characters more commonly observed in species belonging to the T. crassula group. Nonetheless, it possesses involute ptyxis, subpetiolate leaves (Fig. 28E), saccate cincinni bracts (Fig. 28F, H, I), style as long as the stamens (Fig. 28H, I), seeds not cleft towards the embryotega and hilum shorter than ½ the length of the seed (Fig. 28J). These characters undoubtedly place T. tenella and related species (i.e. T. atlantica and T. tucumanensis) in the T. fluminensis group (Pellegrini 2017). Due to its peculiar morphology, T. tenella can be confused with species belonging to the T. crassula and T. fluminensis groups. Tradescantia tenella can be confused with T. seubertiana from the T. crassula group, due to their delicate habit, definite base, erect and succulent stems, unequal cincinni bracts and pink flowers. Nonetheless, it can be differentiated by its generally densely branched to fruticose stems (vs. little branched, branching at the base or rarely branching at the upper half in T. seubertiana), subpetiolate leaves with impressed secondary veins (vs. sessile with inconspicuous secondary veins), blades generally sparsely hirsute to hirsute with ciliolate margins (vs. always glabrous with glabrous margins), saccate cincinni bracts (vs. not saccate), pistil as long as the stamens (vs. longer than the stamens), seeds with testa rugose and not cleft towards the embryotega (vs. costate and cleft) and hilum shorter than ½ the length of the seed (vs. longer than ½ the length of the seed). In the T. fluminensis group, T. tenella can be confused with T. mundula due to their generally reduced stature, subpetiolate leaves and blades generally abaxially vinaceous. However, it can be easily differentiated due to its definite base (vs. indefinite in T. mundula), erect stems (vs. prostrate), leaf-blades generally sparsely hirsute to hirsute (vs. sparsely strigose to strigose), unequal cincinni bracts (vs. equal), sepals glandular pubescent (vs. velutine), petals ranging from white to pink (vs. always white), seeds with rugose testa (vs. costate) and hilum shorter than ½ the length of the seed (vs. equal to ½ the length of the seed). Tradescantia tenella is unquestionably morphologically closely related to T. atlantica and T. tucumanensis, forming the T. tenella complex. The species in this complex share the definite base, erect stems, chartaceous leaf-blades, flowers that range from white to pink, seeds with rugose testa and hilum always shorter than ½ the length of the seeds (Pellegrini 2017), being differentiated by stem consistency, the presence of a subpetiole, type and distribution of hairs in the sepals and petal morphology (see identification key). Diagnosis. Similar to T. tenella due to its definite base, densely branched stems, hirsute leaves, conspicuous secondary veins, saccate and strongly unequal cincinni bracts, keeled sepals, flat petals, pistil the same length as the stamens, seeds with rugose testa and hilum shorter than ½ the length of the seed. It can be differentiated by its prostrate stems with ascending apex, sessile to subpetiolate leaves, hyaline to light brown hairs, Description. Herbs ca. 20-55 cm tall, with a definite base, terrestrial or rupicolous, rarely epiphytes. Stems erect, sometimes prostrate with ascending apex, succulent, little to densely branched; internodes 1.6-12.1 cm long at base, distally shorter, medium to dark green or vinaceous, sometimes with green longitudinal striations or spots, velutine to hispid, sometimes becoming glabrous with age, with a leaf-opposed longitudinal line of short, uniseriate, hyaline hairs in the terminal portion of the stems. Leaves distichously-alternate, sessile to subpetiolate; ptyxis involute; sheaths 0.4-1 cm long, medium green, with longitudinal vinaceous striations, sparsely velutine to hispid, margin setose, hairs hyaline to light brown; petiole 0.2-1.2 cm long to indistinct in the apical leaves; blades 1.1-8.7 × 0.9-3.2 cm, narrowly lanceolate to lanceolate or ovate to broadly ovate, flat, membranous to chartaceous, sparsely hispid to hispid on both sides, hairs hyaline to light brown, adaxially medium to dark green, abaxially light to medium green or vinaceous, turning medium brown to olive-green when dry, base cordate to round, margin green, ciliate, slightly revolute, apex acute to acuminate; midvein conspicuous, adaxially impressed, secondary veins conspicuous, adaxially impressed, abaxially inconspicuous, becoming evident when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles (0.8-2.0-)3.4-8.2 cm long, velutine to hispid, with a leaf-opposed longitudinal line of short, uniseriate hairs, in the terminal portion of the stems, hairs hyaline to light brown; cincinni bracts 1.1-4.8 × (0.5-)1-2.7 cm, leaf-like, unequal to strongly unequal to each other, rarely similar to each other, elliptic or ovate to broadly ovate, sparsely hispid, hairs hyaline to light brown, adaxially medium to dark green, abaxially light to medium green or vinaceous, base cordate to obtuse, saccate, margins ciliolate to hispid, hairs hyaline to light brown, slightly revolute, apex acute to acuminate; double cincinni  Description. Herbs ca. 30-80 cm tall, with an indefinite base, terrestrial, rupicolous or epiphytes. Stems prostrate with ascending apex, succulent to slightly fibrous, little to densely branched; internodes 2.8-10 cm long at base, distally shorter, light to medium to dark green or reddish-purple to vinaceous, glabrous to sparsely pilose, with a leaf-opposed longitudinal line of short, uniseriate, hyaline to light brown hairs in the terminal portion of the stems. Leaves distichously-alternate, sessile; ptyxis involute; sheaths 0.5-2.3 cm long, light to medium to dark green or reddish-purple to vinaceous, glabrous to pilose to sparsely hispid, margin densely setose, hairs hyaline to light brown; blades 3.8-19.1 × 1-3.5 cm, linear lanceolate to lanceolate or narrowly lanceolate to lanceolate, flat, chartaceous, sometimes membranous, glabrous on both sides or adaxially glabrous and abaxially pilose, hairs hyaline to light brown, adaxially medium to dark green, abaxially light to medium green, rarely vinaceous, turning dark brown to black when dry, base truncate to amplexicaulous or round, margins green, ciliolate to ciliolate, flat, apex acuminate to caudate; midvein conspicuous, adaxially impressed, secondary veins conspicuous, adaxially slightly impressed to impressed, abaxially prominent, becoming more evident on both sides when dry. Synflorescences terminal or axillar in the distal portion of the stems, composed of a solitary main florescence, 1-4 per leaf axis. Inflorescences (main florescences) consisting of a pedunculate double-cincinni fused back to back; peduncles 0.5-4.3 cm long, light to medium to dark green, glabrous to pilose, with a dense longitudinal line of short, uniseriate, hyaline to light brown hairs; cincinni bracts 0.5-1.5(-2.3-6.2) × 0.2-1(-1.4) cm, similar to each other, cordate to broadly cordate, rarely lanceolate, spathaceous, rarely leaf-like, glabrous or pilose to sparsely hispid, medium to dark green, abaxially light to medium green, base cordate to obtuse, saccate, margins ciliolate to ciliolate, flat, apex acute, rarely acuminate; double Distribution and habitat. Argentina and Brazil (states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul) and Paraguay; in the Atlantic Forest, Cerrado and Chaco domains (Fig. 33). It can be found growing as terrestrial and epiphyte understorey in shaded and moist forests.

Tradescantia umbraculifera
Phenology. It was found in bloom and fruit throughout the year but peaking between August and February.
Etymology. The epithet "umbraculifera" means "carrying several umbrellas", making reference to the many inflorescences per leaf axil this species generally produces and, most importantly, to the its small spathaceous cincinni bract.
Conservation status. Tradescantia umbraculifera possesses a wide EOO (ca. 764,678.067 km 2 ), forming dense subpopulations in shady and moist understorey. Thus, in accordance with the IUCN recommendations (IUCN 2001), it should be considered Least Concern (LC).
Comments. Tradescantia umbraculifera is a member of the T. fluminensis group (Pellegrini 2017), due to its indefinite base, prostrate stems (Fig. 32A), involute ptyxis, leafblades with impressed secondary veins (Fig. 32C), saccate cincinni bracts (Fig. 32E-G) and seeds not cleft towards the embryotega (Fig. 32K). Furthermore, dried specimens of T. umbraculifera acquire a peculiar dark brown to black colouration, which is recorded in T. subg. Austrotradescantia for T. chrysophylla, T. cymbispatha and some specimens of T. fluminensis. Nonetheless, it is one of the most peculiar species in T. subg. Austrotradescantia, due to its generally acuminate to caudate leaf-blades (Fig. 32C), numerous inflorescences per leaf axis (Fig. 32E, F), spathaceous cincinni bracts (Fig. 32E-G), white to vinaceous pedicels (Fig. 32H), pistil longer than the stamens (Fig. 32G) and hilum longer than ½ the length of the seed (Fig. 32K). This combination of characters differentiates T. umbraculifera from all remaining species of T. subg. Austrotradescantia. Smaller specimens of T. umbraculifera can be more easily confused with T. fluminensis but can be easily differentiated based on inflorescence and seed characters. Despite the distinction between T. umbraculifera and T. fluminensis being generally clean-cut, some specimens were especially challenging to certainly identify. This is mainly due to the presence of leaf-like, instead of spathaceous cincinni bracts (easily observable in herbarium specimens) and intermediate floral features between the two species (observable only in fresh specimens; Fig. 32J), such as: the colour of the pedicels, shape of the petals, length and density of the filaments hairs and pistil length. These specimens are hypothesised to represent naturally occurring hybrids between both species, since they were observed in areas where both T. umbraculifera and T. fluminensis were known to occur. However, due to the lack of reproductive, hybridisation and cytological studies, I have chosen to tentatively recognise these specimens under a broader sense of T. umbraculifera. Further studies might confirm my assumptions of the natural occurrence of hybrids between T. umbraculifera and T. fluminensis. Despite the small morphological resemblance, herbarium specimens of T. umbraculifera have been previously confused in Southern Brazil with T. tenella. Both species share only a handful of morphological characters, all of them being synapomorphies of the T. fluminensis group. Tradescantia umbraculifera can be easily differentiated from T. tenella due to its robust habit (vs. generally small in T. tenella), indefinite base (vs. definite), prostrate stems (vs. erect), sessile leaves (vs. subpetiolate), 1-4 main florescences per leaf axil (vs. always 1), cincinni bracts spathaceous and equal (vs. leaf-like and unequal) flowers 1.3-2.2 cm diam. (vs. 0.4-1 cm diam.), petals always white (vs. ranging from white to pink), pistil longer than the stamens (vs. equal), seeds with costate testa (vs. rugose) and hilum longer than ½ the length of the seed (vs. shorter than ½ the length of the seed).
Despite being in different morphological groups, herbarium specimens of T. umbraculifera have also been confused with T. crassula. This might be due these species robust habit, sessile leaves, sepals with hairs restricted to the dorsal keels, petals always white, pistil longer than the stamens and hilum longer than ½ the length of the seed. Nonetheless, T. umbraculifera can be easily differentiated by its indefinite base (vs. definite in T. crassula), prostrate stems (vs. erect), 1-4 main florescences per leaf axil (vs. always 1), cincinni bracts spathaceous and saccate (vs. leaf-like and non-saccate) and seeds not cleft towards the embryotega (vs. cleft).

Final remarks
As stated by Pellegrini et al. (2017) and shown by Hunt (1975Hunt ( , 1980Hunt ( , 1986 and Pellegrini (2017), Tradescantia is a taxonomically complicated and morphologically diverse genus. Its morphology has hitherto been unsatisfactorily explored and many morphological characters historically used in its taxonomy are not completely reliable on their own. Further studies are still needed in Tradescantia, especially regarding the taxonomy within its subgenera. Tradescantia subg. Campelia, was considered by Pellegrini (2017) to be composed of ca. 15 species. However, ongoing studies in collaboration with Dr. David R. Hunt and Dr. Jason R. Grant, have revealed several undescribed species, and highlighted the need for more thorough studies in some species complexes (e.g. T. commelinoides and T. zebrina) and the need to revisit their taxonomy (Pellegrini et al. in prep.). Tradescantia subg. Mandonia is still poorly studied and understood and a taxonomic revision seems pressing. As exposed by Pellegrini (2017), T. subg. Tradescantia is still a taxonomically challenging group, with several poorly understood species, blurry specific boundaries and several putative natural hybrids. Nonetheless, the number of still undescribed species seems to be very low. Tradescantia subg. Setcreasea is taxonomically well-understood thanks to Hunt (1975Hunt ( , 1976, but lacks an updated identification key. Further studies in this subgenus should also address reproductive biology and population genetics studies. This study presented the first complete taxonomic revision for one of the five subgenera of Tradescantia, proposed by Pellegrini (2017). I recognise 13 species, most of them widely distributed and presenting considerable morphological variation, as was also observed by Anderson and Woodson Jr. (1935) for the species of Tradescantia, native to the USA. The recognition of narrowly distributed and poorly-circumscribed taxa renders the taxonomy of Tradescantia unnecessarily complicated and most prob-ably unnatural. The specific boundaries accepted by me for the species of T. subg. Austrotradescantia reflect extensive fieldwork throughout the Neotropical region, cultivation of almost all species of the subgenus and an understanding of the genus as a whole. My observations on dried and living specimens suggest that most variation in the genus might be ecologically related, with some changes being also putatively controlled by epigenetics and cytology. Unless focused studies on the reproductive and genetic features of these species are conducted, I strongly recommend that the broader species concepts herein proposed are followed.