Research Article |
Corresponding author: Marco O. O. Pellegrini ( marcooctavio.pellegrini@gmail.com ) Academic editor: Peter Boyce
© 2018 Marco O. O. Pellegrini, Charles N. Horn, Rafael F. Almeida.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Pellegrini MOO, Horn CN, Almeida RF (2018) Total evidence phylogeny of Pontederiaceae (Commelinales) sheds light on the necessity of its recircumscription and synopsis of Pontederia L. PhytoKeys 108: 25-83. https://doi.org/10.3897/phytokeys.108.27652
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A total evidence phylogeny for Pontederiaceae is herein presented based on new morphological and previously published molecular data. Our results led us to re-circumscribe Pontederia to include Monochoria, Pontederias.s. and the polyphyletic Eichhornia. We provide the needed ten new combinations and 16 typifications, arrange a total of 25 accepted species (six representing re-established names) in 5 new subgenera. Furthermore, we provide an identification key for the two genera accepted by us in Pontederiaceae, an identification key to the subgenera, identification keys to the species of each subgenus and commentaries on Pontederias.l., as well as for each subgenus and each species.
Aquatic flora, Eichhornia , Monochoria , pickerelweed, Reussia , water-hyacinth
Pontederiaceae is a small aquatic monocot family, placed in Commelinales as sister to Haemodoraceae, with both families being sister to Philydraceae (
Recently, Heteranthera was recircumscribed to include Hydrothrix Hook.f. and Scholleropsis H.Perrier, thus being finally rendered monophyletic (
According to
Here, we present a total evidence phylogeny for Pontederiaceae, based on plastid and morphological data, in order to recircumscribe Pontederia to include Eichhornia and Monochoria and provide an identification key to the genera in Pontederiaceae. We also present a synopsis for Pontederias.l., with an updated description for the genus, propose five new subgenera, provide an identification key to the accepted subgenera of Pontederia and provide identification keys to the species of each subgenus. Finally, we propose the needed 10 new combinations, present six new synonyms and accept a total of 25 species, five of these representing reestablished names. The present study concludes the bi-generic classification of Pontederiaceae initiated by
Specimens from the following herbaria were analysed: AAU, ALCB, B, BA, BAF, BHCB, BHZB, BLH, BM, BOL, BOTU, BR, BRIT, C, CAS, CEPEC, CESJ, COL, CORD, CTES, CVRD, DS, E, EA, ESA, F, FCAB, FLOR, FURB, G, GH, GMUF, GOET, GUA, HAL, HAMAB, HAS, HB, HBR, HERBAM, HNMN, HRB, HRCB, HSTM, HUEFS, HUFSJ, HURB, IAC, IBE, ICN, INPA, IPA, K, KANU, L, LE, LG, LIL, LL, LP, M, MA, MBM, MBML, MG, MO, MVM, MY, NBYC, NY, OS, P, PH, PMSP, PR, PRC, PRE, R, RB, RFA, RFFP, S, SMU, SP, SPF, SRGH, TEX, UEC, UMO, UNA, UPCB, US, USF, VDB, VIC, W and WAG (herbaria acronyms according to Thiers, cont. updated). Fresh specimens, field notes, photographs and specimens for cultivation were gathered by the authors during several field trips across North, Central and South America, between 1980 and 2017. The indumentum and shape terminology follow
Characters were scored mainly from living specimens in the field and specimens in cultivation and later complemented by spirit and herbarium samples from the aforementioned herbaria. When no living or herborised specimens were available for examination, information was taken from published literature. We have studied at least five specimens for each taxon, with the most representative specimen chosen as the voucher for the morphological matrix (Table
Voucher specimens used in the morphological and combined phylogenetic analyses, and Genbank accession numbers for all DNA regions sampled in this study. *Type species of the genus.
Family | Species | Collector & no. | Herbarium acronym | ndhF | rbcL |
---|---|---|---|---|---|
Philydraceae | *Helmholtzia acorifolia F.Muell. | Mueller 1876 | K | EF422989.1 | AF206774.1 |
Philydraceae | *Philydrum lanuginosum Banks & Sol. ex Gaertn. | Banks & Solander s.n. | BM barcode BM000990702 | U41622.2 | U41596.2 |
Haemodoraceae | Anigozanthos flavidus DC. | Brown s.n. | K barcode K000846259 | EF422987.1 | EF422992.1 |
Haemodoraceae | *Xiphidium caeruleum Aubl. | Perdiz 2376 | RB | AF547013.1 | AY149359.1 |
Pontederiaceae | Monochoria cyanea (F.Muell.) F.Muell. | Leichhardt s.n. | K barcode K000873493 | U41613.1 | U41588.1 |
Pontederiaceae | Monochoria korsakovii Regel & Maack | Maack s.n. | K barcode K000873544 | U41615.2 | U41590.1 |
Pontederiaceae | *Monochoria hastata (L.) Solms | Hermann s.n. | BM barcode BM000621681 | U41614.1 | U41589.1 |
Pontederiaceae | Monochoria vaginalis Burm.f. | Boeea 8471 | US | U41616.1 | KX527476.1 |
Pontederiaceae | Eichhornia crassipes (Mart.) Solms | Martius 60 | M | FJ861142.1/ U41599.2 | FJ861142.1/ EF422991.1 |
Pontederiaceae | Eichhornia diversifolia (Vahl) Urb. | Harley 10248 | RB | U41600.1 | U41575.1 |
Pontederiaceae | *Eichhornia azurea (Sw.) Kunth | Martinelli 18669 | RB | U41598.1 | U41573.1 |
Pontederiaceae | Eichhornia heterosperma Alexander | Smith 2290 | NY | U41601.1 | U41576.1 |
Pontederiaceae | Eichhornia paniculata (Spreng.) Solms | Machado 574 | RB | U41603.1 | U41578.1 |
Pontederiaceae | Eichhornia paradoxa (Mart.) Solms | Harley 21401 | K | U41607.1 | U41579.1 |
Pontederiaceae | *Pontederia cordata L. | Barton s.n. | PH barcode PH00038346 | U41617.1 | U41592.1 |
Pontederiaceae | Pontederia lancifolia Muhl. | Muhlenberg 242 | PH | U41618.1 | U41593.1 |
Pontederiaceae | Pontederia rotundifolia L.f. | Alvarenga 952 | RB | U41620.1 | U41595.1 |
Pontederiaceae | Pontederia ovalis Mart. | Pellegrini 474 | RB | U41619.1 | U41594.1 |
Pontederiaceae | Pontederia sagittata C.Presl | Catharino 342 | RB | U41621.1 | U41597.1 |
Pontederiaceae | Heteranthera gardneri (Hook.f.) M.Pell. | Gardner 1863 | K | U41606.2 | U41582.1 |
Pontederiaceae | Heteranthera rotundifolia (Kunth) Griseb. | Walter 6644 | RB | U41610.1 | U41585.1 |
Pontederiaceae | Heteranthera limosa (Sw.) Willd. | Assunção 721 | RB | U41608.2 | U41583.1 |
Pontederiaceae | Heteranthera zosterifolia Mart. | Fontana 8316 | RB | U41612.1 | U41587.1 |
Pontederiaceae | Heteranthera seubertiana Solms | Gardner 1864 | BM | U41611.1 | U41586.1 |
Pontederiaceae | Heteranthera oblongifolia Mart. ex Schult. & Schult.f. | Araújo 38 | RB | U41609.1 | U41584.1 |
Data were entered into a matrix of characters per taxa using the software Mesquite 3.20 (
Sequences of the genes ndhF and rbcL were retrieved from GenBank for 26 taxa representing all currently accepted genera in Pontederiaceae, including outgroups Anigozanthos Labill. and Xiphidium Aubl. (Haemodoraceae) and the tree was rooted with Philydraceae. All sequences were aligned using Muscle (
Combined analyses of the plastid regions and plastid+morphology datasets were performed. Prior to combining our data, we performed the incongruence length difference (ILD) test (
For the DNA partitions of the model-based approach, we selected the model using hierarchical likelihood ratio tests (HLRT) on J Modeltest 2 (
The cladistic analysis retrieved 228 equally parsimonious trees with 209 steps, Consistency Index (CI) of 0.5913, Homoplasy Index (HI) of 0.4087, Retention Index (RI) of 0.8618 and Rescaled Consistency Index (RC) of 0.5096. All 96 coded characters were parsimony-informative. The strict consensus (Fig.
Strict consensus tree (length=209 steps; CI=0.5913; RI=0.8618) recovered by the morphological dataset, showing the character state optimisations at each node of the cladogram, represented by circles. In each circle, the numbers above and below represent the character and character state numbers, respectively (as presented in Suppl. material
The Haemodoraceae+Pontederiaceae clade is supported by seven characters: the presence of septal nectaries (Character 44), perianth 6-lobed (Character 58, plesiomorphic), perianth with 3+3 arrangement (Character 59, plesiomorphic), epipetalous stamens (Character 66, homoplastic), stamens dimorphic (Character 69), endothecium with a basal thickening (Character 72) and non-tectate-columellate exine (Character 76). Pontederiaceae is recovered as monophyletic with high statistical support (BS=100; BI=7; Fig.
Majority-rule tree recovered for the morphological and plastid datasets. Morphology: bootstrap support values are depicted over the branches, while Bremer Index support values are depicted under the branches. Plastid: posterior probability values are depicted over the branches. Yellow: Philydraceae. Orange: Haemodoraceae. Blue: Heterantheras.l. Pink: Pontederias.l.
Heterantherasensu
Pontederias.l. is also recovered as monophyletic with high statistical support (BS=93; BI=6; Fig.
The ndhF characters represented 503 characters of the plastid dataset, with GTR+G as the nucleotide model selected. The rbcL characters represented 1355 characters of the plastid dataset, with HKY+G+I as the nucleotide model selected. The plastid dataset represented 1858 characters, of which 241 characters were variable and 119 characters were parsimony-informative. The plastid Bayesian analysis recovered a mostly resolved tree with 23 well-supported clades (>PP 95%) (Fig.
Topologies produced by MP and BI analyses, based on the combined plastid + morphology datasets, were highly congruent and provided higher support for more clades than the results based on independent datasets (Fig.
The topologies recovered from the combined plastid and the total evidence datasets strongly corroborate the bi-generic circumscription of Pontederiaceae suggested by
The monophyly of Pontederiaceae was rarely, if ever, questioned by previous authors. Perhaps for this reason, little attention was ever given to the family’s putative morphological synapomorphies. Amongst the 18 morphological synapomorphies recovered for Pontederiaceae, one was previously suggested by
Almost, if not all, leaf synapomorphies recovered for Pontederiaceae seem to be directly correlated. These characters seem to be related to the adaptive shift to a completely aquatic lifestyle in the family and an adaptation to changes in water level. The leaves of Pontederiaceae are characteristically dimorphic, being morphologically divided into sessile and petiolate leaves (
As aforementioned, the leaves of Pontederiaceae are dimorphic, with both sessile and petiolate leaves being produced at different times in the plants’ life. Sessile leaves represent the plesiomorphic state and are the first ones produced after seed germination. They vary in number from 5–many per plant and allow plants to become established in a submersed habitat (
The presence of a leaf sheath projection is striking in Pontederiaceae, with its morphology being relevant to the systematics of the family. Ligules and ligule-like structures are recorded for several members of Embryopsida, being especially common in some lycophytes (i.e. Selaginellales and Isoëtales) and several monocots (i.e. Alismatales, Arecales, Asparagales, Commelinales, Dioscoriales, Poales and Zingiberales) (
Heteranthera Ruiz & Pav. A–D habit: A emerged and flowering population of H. gardneri (Hook.f.) M.Pell. during the dry season B floating specimen of H. reniformis Ruiz & Pav. C emergent habit with floating and emerged leaves of H. rotundifolia (Kunth) Griseb. D habit of H. dubia (Jacq.) MacMill., showing the persistent sessile leaves E petiolate leaf of H. pumila M.Pell. & C.N.Horn, showing the lack of a pulvinus F Ligule and inflorescence of H. pumila G–J flowers: G pseudanthium of H. gardneri H H. reniformis I H. rotundifolia J H. zosterifolia Mart. A by A.P. Fontana B, H by C.N. Horn C, I by A. Popovkin D by S.R. Turner E, F by M.O.O. Pellegrini G by C.P. Bove and J by S.S. Oliveira.
Out of the reproductive synapomorphies recovered by us for Pontederiaceae, some of them seem to be related to pollination, while the others seem to be related to fruit dispersal. Sessile flowers are recovered by us as a synapomorphy of Pontederiaceae, with the sole reversion occurring in Monochoria. This character seems to be directly related to another reproductive synapomorphy for the family (i.e. perianth connate to part of the receptacle and the filaments producing a conspicuous tube). Pedicel and floral tube length seem to be inversely correlated, with tube elongation helping with the floral display by elevating the perianth lobes. Added to that, the contraction of the pedicel might also provide extra stability for heavier floral visitors that require landing platforms in order to properly visit flowers (e.g. butterflies). Alternatively, the reversion from sessile to pedicellate flowers in Monochoria might have played a key role, by giving flowers the needed mobility in order to avoid floral damage during buzz pollination (
The first synapomorphy related to diaspore dispersal is the deflexed position of the inflorescence at post-anthesis and in fruit. This shift in the inflorescence position during fruit development will almost certainly allow the mature fruits to reach the water after their maturity. The deflexed inflorescences also elongate in length, which ultimately places the maturing fruits at or under the water surface. This seems to be the first step in diaspore dispersion in most species of Pontederiaceae. The following adaptations are related to increasing the floatation period of the diaspores. The first and most obvious seems to be the presence of an anthocarp. According to
All 18 synapomorphies recovered by us for Pontederias.l. are suggested here for the first time. Sand-binding roots were recovered by
The presence of leaves with pulvinate petioles in Pontederias.l. is easily observed in the field, since most pulvini are lighter or darker than the rest of the petiole. On the other hand, in dried specimens, this difference in colouration is only sometimes maintained, making this character not always obvious to untrained eyes. Added to that, the pulvini in Pontederias.l. are seldom swollen, as would be expected in most eudicot plants with articulated leaves. Nonetheless, this feature seems to be key for the emergent and floating species, especially the perennial ones, since they are subjected to the greatest amount of environmental variation. Floating species like E. crassipes are easily dragged by water currents, forcing all leaf-blades to change their position in order to better absorb sunlight. Perianth-coiling at post-anthesis seems to be poorly documented in the literature for most Angiosperm families and more so in the monocots. It is known to occur in the monocots only in the distantly related Bromeliaceae (Poales), being characteristic to some genera of subfamilies Pitcairnioideae and Puyoideae (Smith et al. 1998;
Tristyly is an extremely rare type of heterostyly, recorded for a handful of families, only two being monocots (i.e. Amaryllidaceae and Pontederiaceae;
In Pontederiaceae, three different patterns in perianth-lobe shape can be observed: (1) perianth lobes all equal, thus producing an actinomorphic perianth (e.g. H. dubia); (2) equal to subequal in the same whorl, producing either actinomorphic or zygomorphic perianths, depending on the presence of a nectar guide [e.g. actinomorphic in M. hastata (L.) Solms and zygomorphic in E. crassipes]; and (3) unequal perianth lobes, with more than one morph in the same whorl, producing strongly zygomorphic perianths (e.g. H. gardneri). In Commelinales, the perianth lobes pattern seems to be extremely variable, being equal in the same whorl in Hanguanaceae, unequal in Philydraceae (due to the fusion of three posterior lobes) and variable in Commelinaceae and Haemodoraceae (Pellegrini, pers. observ.). In Commelinaceae, sepals are almost invariably different from the petals, except in Palisota Rchb. ex Endl. in which the sepals are characteristically petaloid (
Out of the four synapomorphies recovered for the E. paniculata group, two had been previously proposed by
Monochoria comprises species with extremely autapomorphic morphology, being traditionally grouped based on their: pedicellate, actinomorphic and enantiostylous flowers, basally connate perianth and its basifixed and poricidal anthers (
Despite being well-known, E. crassipes possesses the most peculiar vegetative morphology in the polyphyletic Eichhornia and one of the most peculiar in the family as a whole. It is so peculiar that specimens are easily identified, even when lacking any reproductive structures (Pellegrini and Horn, pers. observ.). It is the only species in the family to possess a free-floating growth form, the only one to produce stolons and the only one to possess inflated petioles. Nonetheless, one of the most peculiar characters in E. crassipes has been greatly disregarded by most specialists in the family. Castellanos (1958) was one of the first to properly describe and illustrate the flabellate ligules of E. crassipes. All synapomorphies recovered for E. crassipes seem to be directly related to its peculiar free-floating growth form, which also enabled it to become the most troublesome weed of the world (
From all the recovered clades in Pontederias.l., Pontederias.s. goes hand-in-hand with Monochoria in the number of reproductive synapomorphies. Out of the eight recovered synapomorphies for this clade, six are reproductive, with only the presence of epithelial cells in the septae, which are shared with Monochoria, being homoplastic. All the remaining five reproductive synapomorphies are directly correlated, but their evolutionary chronology is much harder to infer. The most parsimonious view is probably that all characters were triggered concomitantly by the appearance of the pseudomonomerous ovary, which caused the change in placentation morphology and ovule number. The abortion of most of the gynoecium might have caused a key shift in the reproductive strategy in this lineage from investing in a great number of small seeds with little chance of reaching maturity, to investing into a single big seed with a good amount of provision and guaranteeing that it has a greater chance of reaching maturity. The smooth testa seems to be a simple byproduct of negative selection of ornamentation, since the seeds stopped being individually dispersed with the change of reproductive strategy. Finally, the achene gives this lineage a great evolutionary advantage since it is easily dispersed by water, with a long floatation period due to its thick parenchymatous walls. Furthermore, many species also possess complex ornate achenes, with teeth and spikes that efficiently stick to fur, feathers, fabric etc., most likely having animals as their primary dispersers (Pellegrini, pers. observ.).
With the present recircumscription of Pontederia, Pontederiaceae now is organised in two monophyletic genera (i.e. Heteranthera and Pontederia). As stated by
1 | Sessile leaves spirally-alternate, petiolate leaves sometimes present in mature specimens, when present non-pulvinate, blade membranous; inflorescence reduced to a solitary cincinnus; stamens (1–)3, staminodes sometimes present, septal nectaries absent, stigma unevenly trilobate |
Heteranthera Ruiz & Pavón (Fig. |
– | Sessile leaves distichously-alternate, petiolate leaves always present in mature specimens, pulvinate, blade chartaceous to coriaceous; inflorescence a 2–many branched thyrsi (rarely reduced to a solitary flower); stamens 6, staminodes absent, septal nectaries present (if absent, then flowers pedicellate and anthers poricidal), stigma capitate or trilobate, rarely trifid |
Pontederia L. (Figs |
Pontederia cordata L.
Herbs perennial or annual, aquatic to amphibious, erect-emergent, procumbent-emergent or free-floating. Roots thin, fibrous or spongy. Rhizome short and generally inconspicuous. Stems trailing to erect, delicate to spongy, branching at the base, rarely branching at the upper half, rooting at the basal nodes or along the whole stem; internodes reduced to elongate, producing stolons or not. Sessile leaves distichously-alternate, congested at the apex of the stem, submerged, deciduous or persistent in mature plants, blades linear to linear-obovate, membranous, rarely chartaceous. Petiolate leaves distichously or spirally-alternate, congested at the apex of the stem or evenly distributed along the stem, floating or emergent, ligule truncate or with a flabellate projection; petioles conspicuous, rarely indistinct, inflated or not; blades elliptic to lanceolate or ovate to cordate to reniform or obovate to rounded, chartaceous to coriaceous. Synflorescence composed by a solitary main florescence subtended by a vegetative, petiolate leaf. Main florescences (inflorescences) axillary or apparently terminal, consisting of a pedunculate, many-branched thyrse, rarely a reduced thyrse; inflorescence leaf with or without an inflated leaf-sheath; basal bract flat or tubular; cincinnus’ bract absent; cincinni (1–3–)4 – many per thyrse, alternate or fascicle-like, 1 – many-flowered, sessile or pedunculate, internodes contracted, rarely elongate; bracteoles absent, rarely present. Flowers bisexual, sessile or pedicellate, chasmogamous, pseudo-homostylous or tristylous, enantiostylous, zygomorphic, perianth connate usually forming a tube (hypanthium), rarely only basally fused, campanulate or infundibuliform or hypocrateriform, white to light pink to pink to mauve to pale lilac to lilac to bluish-lilac to purple, lobes 6 (3 outer and 3 inner), elliptic to oblong to obovate, 3 superior and 3 inferior, rarely 5 superior and 1 inferior, the central superior lobe generally with a nectar guide, consisting of 1–2 yellow to green spots, generally surrounded by a dark purple to bluish-purple, rarely white blur, spirally-coiling or revolute at post-anthesis, deliquescent or not; stamens 6, epipetalous, dimorphic (the superior 3 shorter than the inferior 3) or unequal (1 inferior longer with a differently coloured anther), filaments J-shaped or recurved-decurved, terete, glabrous to glandular-pubescent, anthers dorsifixed, sometimes basifixed, rimose or poricidal, oblong to elliptic or sagittate; ovary ellipsoid to oblongoid, glabrous, locules 3, (1–)3 fertile, (1–)multi-ovulate, placentation axial or pendulous, septal nectaries generally present, rarely absent, style J-shaped, glabrous to glandular-pubescent, stigma capitate to trilobate, rarely trifid. Fruit a capsule with loculicidal or irregular dehiscence, rarely an achene, ellipsoid to oblongoid to subglobose or ovoid, rarely pyriform, light to medium brown, apiculate due to persistent style base; anthocarp thin or hardened, smooth or ridged, ridges ornamented or not. Seeds oblongoid or ellipsoid or subglobose to broadly oblongoid or ovoid or curved narrowly ovoid, brown to light-brown, testa longitudinally conspicuously to inconspicuously winged, rarely smooth, when present, wings membranous and testa also transversally striated between each wing; funiculi generally persistent, hilum punctate; embryotega dorsal, not prominently apiculate, darker than the rest of the seed.
Pontederia currently comprises 26 mainly Neotropical species. Almost all Paleotropical species belong to P. subg. Monochoria (C.Presl) M.Pell. & C.N.Horn comb. et stat. nov.; except for P. natans P.Beauv., which is restricted to Africa and is a member of P. subg. Eichhornia (Kunth) M.Pell. & C.N.Horn comb. et stat. nov. Species in Pontederia can range from paludal to free-floating plants, thus occurring in a wide range of water bodies, from perennial to temporary, but most commonly in slow or stagnated water.
The circumscription adopted by us is almost equivalent to the original one proposed by
1 | Basal bract commonly with a caudate apex, rarely leaf-like; flowers pedicellate, enantiostylous, perianth only basally connate, campanulate; stamens with filaments connate forming a petalo-staminal tube, anthers basifixed, poricidal; septal nectaries absent |
Pontederia subg. Monochoria (C.Presl.) M.Pell. & C.N.Horn (Fig. |
– | Basal bract with an acute to acuminate to aristate apex, rarely caudate; flowers sessile, non-enantiostylous, perianth connate forming a conspicuous tube, infundibuliform or hypocrateriform; stamens with free filaments, anthers dorsifixed, rimose; septal nectaries present | 2 |
2 | Ovary 1-locular by abortion, fertile locule 1-ovulate, placentation pendulous; fruit an achene, anthocarp hardened, ridges sinuate, toothed or echinate; seeds smooth |
Pontederia subg. Pontederia (Fig. |
– | Ovary 3-locular, locules many-ovulate, placentation axial; fruit a capsule, anthocarp thin to thickened, if thickened ridges smooth; seeds longitudinally winged | 3 |
3 | Herbs procumbent-emergent, stems elongate; sessile leaves late deciduous, rarely persistent in mature plants, petiolate leaves distichously-alternate, evenly distributed along the stem; perianth infundibuliform, style glabrous |
Pontederia subg. Eichhornia (Kunth) M.Pell. & C.N.Horn (Fig. |
– | Herbs erect emergent or free-floating, stems inconspicuous; sessile leaves early deciduous, petiolate leaves spirally-alternate, congested at the apex of the stem; perianth hypocrateriform, style glandular-pubescent | 4 |
4 | Herbs stoloniferous; ligule flabellate, petioles generally inflated; inflorescences deflexed post-anthesis and in fruit, emerging from a non-inflated leaf-sheath, basal bract tubular; flowers ca. 4–6 cm diam., perianth loosely enclosing the developing fruit; seeds oblongoid |
Pontederia subg. Oshunae M.Pell. & C.N.Horn (Fig. |
– | Herbs never producing stolons; ligule truncate, petioles never inflated; inflorescences erect at post-anthesis, emerging from an inflated leaf-sheath, basal bract flat; flowers ca. 2–3 cm diam., perianth tightly enclosing the developing fruit; seeds subglobose to broadly oblongoid |
Pontederia subg. Cabanisia (Klotzsch ex Schltdl.) M.Pell. & C.N.Horn (Fig. |
Cabanisia Klotzsch ex Schltdl., Abh. Naturf. Ges. Halle 6: 176. 1862. Type species (designated here). Cabanisia caracasana Klotzsch ex Schltdl., nom. illeg. (≡ P. paniculata Spreng.).
Herbs perennial or annual, aquatic to amphibious, erect-emergent. Rhizome short and generally inconspicuous. Stems erect, spongy, branching at the base. Sessile leaves early deciduous. Petiolate leaves spirally-alternate, congested at the apex of the stem, emergent, ligule truncate, petioles not-inflated, blades cordate to broadly cordate, rarely elliptic to lanceolate or narrowly ovate. Main florescences (inflorescences) terminal, sessile or pedunculate; inflorescence leaf with an inflated leaf-sheath; basal bract flat; cincinni alternate or fascicle-like, 1–3-flowered, pedunculate, rarely sessile, internodes elongate, rarely contracted. Flowers sessile, chasmogamous, tristylous, zygomorphic, non-enantiostylous, perianth connate forming a tube, hypocrateriform, spirally-coiled at post-anthesis, non-deliquescent and tightly enclosing the developing fruit, lobes 3 superior and 3 inferior, rarely 5 superior and 1 inferior, the central superior lobe with a nectar guide, consisting of 2 yellowish-green to green spots, generally surrounded by a dark purple to bluish-purple, rarely white blur; stamens dimorphic, filaments free from each other, J-shaped, glandular-pubescent, anthers dorsifixed, rimose; ovary with 3 fertile locules, multi-ovulate, septal nectaries present, style glandular-pubescent, stigma capitate to trilobate. Capsules loculicidal, ellipsoid to oblongoid; anthocarp thickened, ridged. Seeds subglobose to broadly oblongoid, testa longitudinally winged.
Pontederia subg. Cabanisia (Klotzsch ex Schltdl.) M.Pell. & C.N.Horn. A habit B–C inflorescence: B young inflorescence, showing the inflated leaf-sheath and flat basal bract with caudate apex C mature inflorescence showing the pedunculate cincinni with elongate internodes D detail of a cincinni, showing (from left to right) an immature floral bud, a pre-anthesis floral bud and a post-anthesis flower E front view of a flower F detail of an immature capsule, showing the ridged anthocarp. All photos of P. paniculata Spreng.; A by C. Willig & L. Nusbaumer, remaining photos by M.O.O. Pellegrini.
Pontederia subg. Cabanisia is composed by P. meyeri (A.G.Schulz) M.Pell. & C.N.Horn comb. nov., P. paniculata Spreng. and P. paradoxa Mart. All three species occur in moist environments or shallow waters, being similar in habit to well-known species of P. subg. Pontederia, such as P. cordata L. Nonetheless, both subgenera can be differentiated based on gynoecium, fruit and seed morphology.
Mainly Central-West and Northeastern Brazil (reaching Argentina and Paraguay), growing in temporary water bodies in the Caatinga, Cerrado and Chaco domains. However, two species have very peculiar disjunctions in their distributions, also occurring in north-western South America (Colombia, Ecuador, Guyana and Venezuela), Central America (Costa Rica, Guatemala and Nicaragua), Antilles (Jamaica) and North America (Mexico).
1 | Petiolate blades without posterior divisions, elliptic to lanceolate or narrowly ovate in outline; inflorescences 2–5-flowered, sessile, cincinni sessile, fascicle-like; perianth arranged in a 5+1 pattern, tube 2–2.5 cm long | P. paradoxa Mart. |
– | Petiolate blades with posterior divisions, cordate to broadly ovate in outline; inflorescences 10–many-flowered, pedunculate, cincinni pedunculate, alternate; perianth arranged in a 3+3 pattern, tube 0.8–1.6 cm long | 2 |
2 | Main axis with a mixture of glandular and eglandular hairs, basal bract with cordate base and caudate apex, basal cincinni 1–2(–3)-flowered, bracteoles present; central superior perianth lobe with one green spot, surrounded by purple striations, all stamens exserted from the floral tube, anthers yellow | P. meyeri (A.G.Schulz) M.Pell. & C.N.Horn |
– | Main axis glandular-pubescent, basal bract with round base and acute to acuminate apex, basal cincinni 4–9-flowered, bracteoles absent; central superior perianth lobe with two green spots, surrounded by a white blur, 3 stamens included and 3 stamens exserted from the floral tube, anthers bluish-lilac to lilac | P. paniculata Spreng. |
Eichhornia meyeri A.G.Schulz, Darwiniana 6: 56. 1942. Lectotype (designated here). ARGENTINA. Chaco, Cote Lai, 25 June 1939, fl., fr., T. Meyer 2640 (SI barcode SI000621!; isolectotypes: GH barcode GH00057534!, LIL barcode LIL000196!).
Restricted to Argentina, Paraguay and Brazil (states of Ceará, Mato Grosso and Mato Grosso do Sul).
Current databases (
Piaropus paniculatus (Spreng.) Small, Fl. S.E. U.S. (ed. 2): 1328. 1913.
Eichhornia paniculata (Spreng.) Solms, Monogr. Phan. 4: 530. 1883.
Cabanisia caracasana Klotzsch ex Schltdl., Abh. Naturf. Ges. Halle 6: 176. 1862, nom. superfluous. Neotype (designated here). BRAZIL. S.loc., fl., Mar 1817, M. Wied s.n. (BR barcode BR0000005188734!).
Pontederia paniculata possesses a peculiarly disjunctive distribution between North-eastern Brazil (states of Alagoas, Bahia, Ceará, Paraíba, Pernambuco, Rio Grande do Norte and Sergipe), north-western South America (Colombia, Ecuador, Guyana and Venezuela), Central America (Nicaragua), Antilles (Cuba and Jamaica) and North America (Mexico).
When describing P. paniculata,
The very evident disjunctions in the distribution of P. paniculata might indicate a species complex, instead of a sole species. Nonetheless, we believe that without proper studies, it would be precocious to re-establish any names or recognise any new taxa at this time.
Eichhornia paradoxa (Mart.) Solms, Monogr. Phan. 4: 531 1883.
Eichhornia schultesiana Seub., Fl. Bras. 3(1): 94. 1847, nom. superfluous. Lectotype (designated here). BRAZIL. Maranhão: Alcântara oppidium at ad Porto de Carvalho, fl., fr., 1817, C.F.P. Martius 2575 (M barcode M0242209!).
Pontederia paradoxa has a disjunctive distribution between Northern and North-eastern Brazil (states of Pará, Bahia, Ceará, and Rio Grande do Norte), north-western South America (Venezuela) and Central America (Costa Rica and Guatemala).
In the original description of P. paradoxa (Schultes and Schultes f. 1830), it is mentioned that the description was based on a Martius collection, from the state of Maranhão, Brazil. After consulting M, we came across the specimen Martius 2575 (M0242209) that matches the protologue in great detail. Thus, it is the obvious choice for a lectotype. Later,
Similarly as P. paniculata, P. paradoxa possesses a highly mind-boggling distribution, which makes us believe that it might actually represent a species complex. Two names are available for the putative disjunctive taxa, but since P. paradoxa in its current circumscription is known for only a handful of specimens, we discourage any taxonomic changes before the species is properly studied.
Monochoria C.Presl, Reliq. Haenk. 1(2): 127. 1827. Type species. Monochoria hastifolia C.Presl., nom. illeg. (≡ P. hastata L.).
Calcarunia Raf., Med. Fl. 2: 106. 1830. Type species. Calcarunia hastata (L.) Raf., nom. inval. (≡ P. hastata L.).
Carigola Raf., Fl. Tellur. 2: 10. 1837. Type species. Carigola hastata (L.) Raf. (≡ P. hastata L.).
Gomphima Raf., Fl. Tellur. 2: 10. 1837. Type species. Gomphima vaginalis (Burm.f.) Raf. (≡ P. vaginalis Burm.f.).
Kadakia Raf. Fl. Tellur. 2: 9. 1837. Type species. Kadakia dilatata (Buch.-Ham.) Raf. (= P. hastata L.). Syn. nov.
Limnostachys F.Muell., Fragm. 1: 24. 1858. Type species. Limnostachys cyanea F.Muell. [≡ P. cyanea (F.Muell.) M.Pell. & C.N.Horn].
Herbs perennial or annual, aquatic to amphibious, erect-emergent or procumbent-emergent. Rhizome short to elongated. Stems erect, spongy, branching at the base. Sessile leaves early deciduous. Petiolate leaves distichously to spirally-alternate, congested at the apex of the stem, sometimes evenly distributed along the stem, floating to emergent, ligule truncate, petioles not-inflated, blades cordate to broadly cordate, rarely elliptic to narrowly ovate. Main florescences (inflorescences) terminal, sessile or pedunculate; inflorescence leaf with an inflated leaf-sheath; basal bract tubular, apex caudate, sometimes acute to acuminate, rarely leaf-like; cincinni alternate or fascicle-like, 1–3-flowered, sessile or pedunculate, internodes elongate, rarely contracted. Flowers pedicellate, chasmogamous, monostylous, actinomorphic or zygomorphic, enantiostylous, perianth connate only at base, campanulate, spirally-coiled at post-anthesis, non-deliquescent and tightly enclosing the developing fruit, lobes 3 superior and 3 inferior, the central superior lobe lacking a nectar guide; stamens unequal, filaments connate forming a petalo-staminal tube, J-shaped or recurved-decurved, glabrous, anthers basifixed, poricidal, dehiscent through two apical pores; ovary with 3 fertile locules, multi-ovulate, septal nectaries absent, style glabrous, stigma capitulate to capitate or trilobate to trifid. Capsules loculicidal, ellipsoid to oblongoid to subglobose; anthocarp thickened, ridged. Seeds cylindrical or ellipsoid to narrowly oblongoid to broadly oblongoid to subglobose or ovoid, testa longitudinally winged.
Pontederia subg. Monochoria (C.Presl) M.Pell. & C.N.Horn. A–B habit: A paludal habit of P. australasica (Ridl.) M.Pell. & C.N.Horn B paludal habit of P. cyanea (F.Muell.) M.Pell. & C.N.Horn C ligule of P. vaginalis Burm.f., showing the truncate apex D–E petiolate leaf-blades: D blade of P. cyanea, showing the lack of a posterior division E blade of P. vaginalis, showing the presence of a posterior division F–G inflorescences: F inflorescence of P. australasica, showing the developed main axis G inflorescence of P. plantaginea Roxb., showing the contracted main axis H front view of a flower of P. korsakowii (Regel & Maack) M.Pell. & C.N.Horn I–J inflorescences at post-anthesis: I erect inflorescence of P. hastata L. bearing flowers at post-anthesis J infructescence of P. hastata, showing the deflexed posture and the elongated pedicels K sections of immature capsules of P. vaginalis, showing developing seeds. A, F by M. Barritt B by R. Cumming C, E, K by P.B. Pelser & J.F. Barcelona D by A. & S. Pearson G by D. Valke H by Ashitaka-f Studio and I & J by Cerlin Ng.
Pontederia subg. Monochoria is composed of ten exclusively Paleotropical species. All species occur in permanently moist environments or shallow waters, growing either as erect or procumbent-emergent, resembling in habit smaller members of P. subg. Pontederia and even some species of Heteranthera. The members of this subgenus are quite unique within Pontederias.l. due to their pedicellate flowers, perianth only basally connate, unequal stamens, basifixed and poricidal anthers and due to the secondary loss of the septal nectaries.
Exclusively Paleotropical (
1 | Filaments without a tooth-like appendage, anthers yellow; stigma trilobate to trifid, with glandular hairs | 2 |
– | Central inferior filament with 1(–2) tooth-like appendage, anthers greyish-blue to purple, remaining stamens with unappendaged filaments and yellow anthers; stigma capitulate to capitate, with eglandular hairs | 3 |
2 | Petiole of the leaves bearing inflorescences shorter than or ca. equal to the length of its leaf-sheath; anthers equal or longer than the filaments | P. australasica (Ridl.) M.Pell. & C.N.Horn |
– | Petiole of the leaves bearing inflorescences 2/5 to 5 times longer than its leaf-sheath; anthers smaller than the filaments | P. cyanea (F.Muell.) M.Pell. & C.N.Horn |
3 | Basal bract leaf-like, rarely reduced to a bladeless sheath, lower cincinni 3–several-flowered; capsules ovoid; seeds cylindrical | P. korsakowii (Regel & Maack) M.Pell. & C.N.Horn |
– | Basal bract always reduced to a bladeless sheath, lower cincinni 1(–2)-flowered; capsules ellipsoid to broadly ellipsoid; seeds oblongoid to ellipsoid or ovoid or subglobose | 4 |
4 | Rhizome robust; petiolate leaves with posterior divisions with acuminate apex; flowers opening from apex to base of the inflorescence; perianth strongly spirally-coiled at post-anthesis | 5 |
– | Rhizome delicate to inconspicuous; petiolate leaves with posterior divisions generally absent, if present posterior divisions with round apex; flowers opening from base to apex of the inflorescence; perianth strongly patent to slightly spirally-coiled at post-anthesis | 7 |
5 | Petioles longitudinally sulcate, leaves narrowly hastate or narrowly sagittate to linear sagittate, narrower than 3 cm wide; inflorescences surpassing the leaves; inner tepals obovate | P. elata (Ridl.) M.Pell. & C.N.Horn |
– | Petioles smooth, leaves hastate to broadly hastate or sagittate to broadly sagittate, equal or broader than 8 cm wide; inflorescences shorter than the leaves; inner tepals elliptic to oblong | 6 |
6 | Petiolate leaf-blades patent, posterior division 2–5 cm long; inflorescences sessile to subsessile, cincinni fascicle-like | P. hastata L. |
– | Petiolate leaf-blades upright, posterior division 7–11 cm long; inflorescences pedunculate, cincinni alternate | P. valida (G.X.Wang & Nagam.) M.Pell. & C.N.Horn |
7 | Leaf blades patent; thyrsi lax, raceme- or fascicle-like, deflexed post-anthesis and in fruit; pedicels ca. as long as the floral buds | 8 |
– | Leaf blades pendulous; thyrsi dense, spike-like, erect post-anthesis and in fruit; pedicels equal to shorter than ½ the length of the floral buds | 9 |
8 | Petiolate leaf-blades without posterior divisions, base round to obtuse, sometimes auriculate; inflorescence 2–7-flowered; seeds oblongoid, longitudinally conspicuously winged | P. plantaginea Roxb. |
– | Petiolate leaf-blades with conspicuous posterior divisions, base characteristically cordate; inflorescence 9–25-flowered; seeds ovoid, longitudinally inconspicuously winged | P. vaginalis Burm.f. |
9 | Petiolate leaves cordate to ovate, leaves bearing inflorescences with petioles (5–)10–12(–16) cm long; seeds ellipsoid to narrowly oblongoid, with 8–10 longitudinal wings | P. africana (Solms) M.Pell. & C.N.Horn |
– | Petiolate leaves narrowly ovate to elliptic to linear, leaves bearing inflorescences with petioles (0.7–)1–2(–4) cm long; seeds subglobose to broadly oblongoid, with 12–14 longitudinal wings | P. brevipetiolata (Verdc.) M.Pell. & C.N.Horn |
Monochoria africana (Solms) N.E.Br., Fl. Trop. Afr. 8: 5. 1901.
Monochoria vaginalis var. africana Solms, Monogr. Phan. 4: 525. 1883. Holotype. B†; Lectotype (designated here). CENTRAL AFRICAN REPUBLIC: Djur Region, Seriba Ghattas, fl., 27 Aug 1869, G.A. Schweinfurth 2296 (PRE barcode PRE0792113-0!; isolectotypes: K barcodes K000321232!, K000321233!).
Angola, Kenya, Malawi, Mozambique, South Africa and Sudan.
Monochoria
australasica
Ridl., J. Straits Branch Roy. Asiat. Soc. 79: 100. 1918. Lectotype (designated by
Restricted to northern Australia.
Monochoria brevipetiolata Verdc., Kirkia 1: 81 1961. Type. GUINEA-BISSAU. Gabú, depressões alagadas de savana entre Pitche e Canquelifá, fl., fr., 18 Sep 1950, J.V.G. Espírito Santo 2777 (holotype: K barcode K000321231!).
Gabón, Gambia, Guinea-Bissau, Ivory Coast, Mali, Níger, Senegal and Sierra Leone.
Monochoria cyanea (F.Muell.) F.Muell., Fragm. 8: 44. 1872.
Limnostachys
cyanea
F.Muell., Fragm. 1: 24. 1858. Lectotype (designated by
Restricted to northern and western Australia.
Monochoria hastata var. elata (Ridl.) Backer, Fl. Males. 4: 258. 1951.
Monochoria
elata
Ridl., J. Straits Branch Roy. Asiat. Soc. 79: 99. 1918. Lectotype (designated by
From Myanmar to Malaysia, Thailand and China.
Monochoria elata (≡ P. elata) was treated by
Monochoria hastata (L.) Solms, Monogr. Phan. 4: 523. 1883.
Carigola hastata (L.) Raf., Fl. Tellur. 2: 10. 1837.
Calcarunia
hastata
(L.) Raf., Med. Fl. 2: 106. 1830. Lectotype (designated by
Bangladesh, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, New Guinea, Philippines, Sri Lanka, Thailand and Vietnam.
Monochoria vaginalis var. korsakowii (Regel & Maack) Solms, Monogr. Phan. 4: 525. 1883.
Monochoria korsakowii Regel & Maack, Mém. Acad. Imp. Sci. Saint Pétersbourg, Sér. 7, 4(4): 155. 1861. Lectotype (designated here). RUSSIA. Ussuri, Keugxa Laa, fl., fr., 1859, R.K. Maack s.n. (LE barcode LE01007092!; isolectotypes: K barcode K000873544!; LE barcodes LE01007090!, LE01007091!, LE01007093!, P barcode P00730337!).
China, India, Indonesia, Japan, Korea, Malaysia, Pakistan, Russia, Sri Lanka and Vietnam.
Monochoria vaginalis var. plantaginea (Roxb.) Solms, Monogr. Phan. 4: 524. 1883.
Monochoria plantaginea (Roxb.) Kunth, Enum. Pl. 4: 135. 1843. Lectotype (designated here). NEPAL: Nathpur, fl., Aug. 1821, N. Wallich 5096 (K barcode K001104737!; isolectotypes: K barcodes K001104733!, K001104734!, K001104735!, K001104736!, K001104738!, K001104739!, K001104740!).
Monochoria vaginalis var. angustifolia G.X.Wang, Acta Phytotax. Sin. 41: 569. 2003. Type. THAILAND. Koksung: in a marshy place, fl., 18 Sep 1984, N. Fukuoka T-36166 (holotype: KYO!; isotypes: A n.v., BKF n.v., L n.v.). Syn. nov.
Boottia mairei H.Lév., Cat. Pl. Yun-Nan 131. 1916. Type. CHINA. Yunnan: Dongchuan [Tangdan], fl., Aug 1912, E.E. Maire s.n. (holotype: E barcode E00386692!). Syn. nov.
Monochoria junghuhniana Hassk., Flora 35: 115. 1852. Lectotype (designated here). INDONESIA. Java, Yogyakarta, Djokjakarta, prope Samas ad affim Opar, fl., s.dat., Junghuhn s.n. (L barcode L0041652!). Syn. nov.
Monochoria linearis (Hassk.) Miq., Fl. Ned. Ind. 3: 549. 1859.
Pontederia linearis Hassk., Flora 25(2, Beibl.): 4. 1842. Type (not found). INDONESIA. Java (L?). Syn. nov.
Monochoria ovata Kunth, Enum. Pl. 4: 665. 1843.
Pontederia ovata Hook. & Arn., Bot. Beechey Voy. 218 1837, nom. illeg. non P. ovata L. Lectotype (designated here). SRI LANKA. Canton, fl., s.dat., Millet s.n. (G barcode G00164757!; isolectotype: E n.v.).
Pontederia cernua L. ex B.D.Jacks., Index Linn. Herb.: 129. 1912, nom. nud.
Pontederia alba Buch.-Ham. ex Wall., Numer. List: 5095 D. 1831, nom. nud.
Pontederia racemosa Buch.-Ham. ex Wall., Numer. List: 5095C. 1831, nom. nud.
Pontederia lanceolata Wall. ex Kunth, Enum. Pl. 4: 135. 1843, pro. syn.
Australia, Bangladesh, Cambodia, China, India, Indonesia, Myanmar, Nepal, Sri Lanka, Thailand and Vietnam.
Monochoria vaginalis, in its current circumscription (
Monochoria vaginalis (Burm.f.) C.Presl ex Kunth, Enum. Pl. 4: 134. 1843.
Gomphima vaginalis (Burm.f.) Raf., Fl. Tellur. 2: 10. 1837.
Monochoria
hastifolia
C.Presl., Reliq. Haenk. 1(2): 127. 1827, nom. illeg. Lectotype (designated by
Widespread throughout Asia (Afghanistan, Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Iran, Japan, Korea, Laos, Malaysia, Myanmar, Nepal, Pakistan, Philippines, Russia, Sri Lanka, Thailand and Vietnam) and Oceania (Australia, Fiji, Papua New Guinea and Pacific Islands).
Monochoria valida G.X.Wang & Nagam., Acta Phytotax. Geobot. 45(1): 41. 1994. Type. CHINA. Hainan: Sanya, Yanglan, fl., 21 Sep 1990, G.X. Wong 901001 (holotype: WH; isotype: KYO!).
Southern China and Thailand.
Monochoria valida (≡ P. valida) was described by
Piaropus Raf., Fl. Tellur. 2: 81. 1837, nom. rej. Type species. Piaropus mesomelas Raf., nom. illeg. (≡ Pontederia crassipes Mart.). Syn. nov.
Pontederia crassipes Mart. [≡ Eichhornia crassipes (Mart.) Solms].
Herbs perennial, aquatic, free-floating. Rhizome short and inconspicuous. Stems inconspicuous, unbranched, producing stolons. Sessile leaves early deciduous. Petiolate leaves spirally-alternate, congested at the apex of the stem, emergent, ligule flabellate, petioles inflated, blades broadly ovate to cordate to reniform. Main florescences (inflorescences) terminal; inflorescence leaf without an inflated leaf-sheath; basal bract tubular; cincinni alternate, 1(–2)-flowered, sessile, internodes contracted. Flowers sessile, tristylous, zygomorphic, non-enantiostylous, perianth connate forming a tube, hypocrateriform, spirally-coiled at post-anthesis, deliquescent and loosely enclosing the developing fruit, 3 superior and 3 inferior, the central superior lobe with a nectar guide, consisting of 1 yellow spot, surrounded by a dark purple to bluish-purple blur; stamens dimorphic, filaments free from each other, J-shaped, glandular-pubescent, anthers dorsifixed, rimose; ovary with 3 fertile locules, multi-ovulate, septal nectaries present, style glandular-pubescent, stigma capitate to trilobate. Capsules loculicidal, oblongoid; anthocarp thin, smooth. Seeds oblongoid, testa longitudinally winged.
Pontederia subg. Oshunae M.Pell. & C.N.Horn. A–B habit: A dense population of the pink-flowered form B detail of a population, showing the free-floating rosettes, stolons and inflated petioles C–D petiolate leaves: C blade D detail of a young leaf showing its blade enclosing the inflated petiole of the presiding leaf E–G inflorescence: E young inflorescence of a lilac-flowered form F inflorescence of a lilac-flowered form at anthesis G inflorescence of a pink-flowered form at anthesis H–J flowers: H oblique view of a lilac flower I detail of the nectar guide J detail of the androecium and gynoecium showing the glandular hairs. All photos of P. crassipes Mart.; A by C. Willig & L. Nusbaumer B by O. Gaubert C by K. Pritchard & S.A. Harris, D–F, H–I by R. Aguilar and G by M.O.O. Pellegrini.
Pontederia subg. Oshunae is monospecific, being composed solely by P. crassipes.
Widespread throughout South America.
The name of this new subgenus derives from the Yoruba words “Oxum”, “Oshun” and “Osun”. These are the names given in the Candomblé religion to the orisha (i.e. a deity that reflects one of the manifestations of God) mother and guardian of freshwater bodies. Oshun is known for her beauty and vanity, being also known as the deity of luxury, pleasure, sexuality, fertility, beauty and love. The sole species accepted in Pontederia subg. Oshunae is commonly named “mãe d’água” (i.e. mother of the freshwaters) in Brazil, also one of the popular names for Oshun. This popular name in Brazil makes reference to the water-hyacinth’s ability to dominate freshwater environments, as well as its ability to produce beautiful flowers.
Eichhornia crassipes (Mart.) Solms, Monogr. Phan. 4: 527. 1883.
Piaropus
mesomelas
Raf., Fl. Tellur. 2: 81. 1837, nom. illeg. Lectotype (designated by
Widespread throughout South America and naturalised worldwide.
Eichhornia Kunth, Enum. Pl. 4: 129. 1843. Type species. Eichhornia azurea (Sw.) Kunth. (≡ P. azurea Sw.).
Leptosomus Schltdl., Abh. Naturf. Ges. Halle 6: 174. 1862. Type species. Leptosomus natans (P.Beauv.) Schltdl. (≡ P. natans P.Beauv.).
Herbs perennial, aquatic, procumbent-emergent. Rhizome short and generally inconspicuous. Stems trailing, spongy, branched to unbranched. Sessile leaves late deciduous, sometimes persistent in mature plants. Petiolate leaves distichously-alternate, evenly distributed along stem, emergent, ligule truncate, petioles not-inflated, blades cordate to ovate or obovate to broadly obovate to rounded. Main florescences (inflorescences) axillary or terminal, pedunculate; inflorescence leaf without an inflated leaf-sheath; basal bract tubular; cincinni alternate, 1–3-flowered, sessile to subsessile, internodes contracted. Flowers sessile, chasmogamous, tristylous or pseudo-homostylous, zygomorphic, non-enantiostylous, perianth connate forming a tube, infundibuliform, revolute at post-anthesis, deliquescent and loosely enclosing the developing fruit, lobes 3 superior and 3 inferior, rarely 5 superior and 1 inferior, the central superior lobe with a nectar guide, consisting of 2 yellowish-green to green spots, generally surrounded by a dark purple to bluish-purple, rarely white blur, coiling or post-anthesis; stamens dimorphic, filaments free from each other, J-shaped, glandular-pubescent, anthers dorsifixed, rimose; ovary with 3 fertile locules, multi-ovulate, septal nectaries present, style glabrous, stigma capitate to trilobate. Capsules loculicidal or with irregular dehiscence, ellipsoid to oblongoid; anthocarp thin, smooth. Seeds subglobose to broadly oblongoid, testa longitudinally winged.
Pontederia subg. Eichhornia (Kunth) M.Pell. & C.N.Horn. A–B habit: A habit of P. heterosperma (Alexander) M.Pell. & C.N.Horn, showing the emerged petiolate leaves B habit of P. diversifolia (Vahl) M.Pell. & C.N.Horn, showing the floating petiolate leaves C–F inflorescence: C 2–3-flowered inflorescences of P. diversifolia, showing the flowers with a yellow nectar guide in the posterior perianth lobes D 1-flowered inflorescence of P. natans P.Beauv., showing the lack of a nectar guide E inflorescence of P. heterosperma, showing the lack of nectar guides in the posterior perianth lobes F morphological variation of inflorescences and perianth colour of P. azurea Sw G front view of a flower of P. azurea H front view of a flower of P. natans. A, B by O. Gaubert C by A.S. Castro D by P. Birnbaum E by H. Medeiros F by L.O.A. Teixeira G by M.O.O. Pellegrini and I by T.C. Buruwate.
Pontederia subg. Eichhornia is composed of four species. All species occur in permanently or seasonal water bodies, growing as procumbent-emergent and resembling in habit some members of P. subg. Monochoria and P. subg. Pontederia. The members of this subgenus are peculiar within Pontederias.l. due to their late deciduous sessile leaves (sometimes persistent throughout the plant’s entire lifespan), perianth infundibuliform, revolute at post-anthesis, deliquescent and loosely enclosing the developing fruit, glandular-pubescent filaments, glabrous styles and anthocarp thin and smooth.
Mainly Neotropical, except for P. natans, which is restricted to continental Africa and Madagascar.
1 | Petiolate leaves floating, blades cordate to ovate, base auriculate to cordate; inflorescences 1–4-flowered; flowers pseudo-homostylous; margins if the internal lobes of the perianth entire | 2 |
– | Petiolate leaves emergent, blades obovate to broadly obovate to rounded, base cuneate; inflorescences 5–many-flowered; flowers heterostylous; margins of the internal lobes of the perianth erose to fimbriate, rarely entire | 3 |
2 | Inflorescences (1–)2–4-flowered; flowers 2–3.2 cm diam., perianth lilac to bluish-lilac, central superior lobe with a yellow spot, surrounded by a purple to bluish-purple blur, filaments glandular-pubescent; capsules 3-valved | P. diversifolia (Vahl) M.Pell. & C.N.Horn |
– | Inflorescences 1(–2)-flowered; flowers 0.7–1 cm diam., perianth purple to mauve, central superior lobe concolorous with the remaining lobes or with a dark purple blur, filaments glabrous; capsules with irregular dehiscence | P. natans P.Beauv. |
3 | Inflorescences axillary, much exceeding the basal bract, main axis glandular-pubescent; perianth with central superior lobe with a yellow spot, filaments glandular-pubescent; seeds monomorphic | P. azurea Sw. |
– | Inflorescences terminal, enclosed or approximately the same size as the basal bract, main axis glabrous; perianth with central superior lobe with a dark purple to bluish-purple blur, filaments glabrous; seeds dimorphic | P. heterosperma (Alexander) M.Pell. & C.N.Horn |
Eichhornia azurea (Sw.) Kunth, Enum. Pl. 4: 129. 1843.
Piaropus azureus (Sw.) Raf., Fl. Tellur. 2: 81. 1837. Type. JAMAICA. s.loc., s.dat., Brown s.n. (holotype: S No. S-R-5196!).
Widespread in the American continent from Mexico to Uruguay.
Eichhornia diversifolia (Vahl) Urb., Symb. Antill. 4: 147. 1903.
Heteranthera diversifolia Vahl, Enum. Pl. 2: 44. 1805. Lectotype (designated here). GUIANA. s.loc., fl., s.dat., L.C. Richard s.n. (C barcode C10017422!).
Antilles (Cuba, Dominican Republic, and Puerto Rico), Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama) and South America (Bolivia, Colombia, Ecuador, French Guiana, Guyana, Suriname, Venezuela and Brazil – states of Acre, Amazonas, Amapá, Pará, Rondônia, Roraima, Tocantins, Alagoas, Bahia, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Sergipe, Goiás, Mato Grosso do Sul, Mato Grosso, Minas Gerais and Rio de Janeiro).
When describing Heteranthera diversifolia,
Eichhornia heterosperma Alexander, Lloydia 2: 170. 1939. Lectotype (designated here). GUIANA. Basin of Rupununi River, Wichabai, fl., fr., 25–26 Oct 1937, A.C. Smith 2290 (NY barcode NY00247522!; isolectotypes: F barcode F0047046F!, G barcode G00168031!, GH barcode GH00255059!, K barcode K000644009!, MO barcode MO-1936311!, NY barcode NY00247521!, P barcode P00730322!, S No. S05-5985!, U barcode U0005719!, US barcode US00091644!).
Antilles (Cuba), Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama) and South America (Bolivia, Colombia, Ecuador, French Guiana, Guyana and Suriname, Venezuela and Brazil – states of Acre, Amazonas, Amapá, Pará, Rondônia, Tocantins, Alagoas, Bahia, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, Rio Grande do Norte, Sergipe, Goiás, Mato Grosso do Sul, Mato Grosso and Minas Gerais).
Eichhornia natans (P.Beauv.) Solms, Abh. Naturwiss. Vereins Bremen 7: 254. 1882.
Leptosomus natans (P.Beauv.) Schltdl., Abh. Naturf. Ges. Halle 6: 174. 1862. Lectotype (designated here). NIGERIA. Benin, fleuve Formosa, fl., fr., s.dat., A.M.F. Palisot de Beauvois s.n. (G on 3ex barcode G00418251!; isolectotype: G-DC on 4ex GDC048496!).
Angola, Benin, Botswana, Burkina Faso, Cameroon, Central African Republic, Chad, Congo, Egypt, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Madagascar, Mali, Mozambique, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, South Sudan, Sudan, Tanzania, Togo, Uganda, Zaire, Zambia and Zimbabwe.
When describing P. natans,
The African E. natans (≡ P. natans) is currently treated as a synonym of the Neotropical Eichhornia diversifolia (≡ P. diversifolia) by all online databases (i.e.
Michelia Adans., Fam. Pl. 2: 201. 1763, nom. illeg. Type species (designated here). Pontederia cordata L.
Narukila Adans., Fam. Pl. 2: 54. 1763, nom. illeg. Type species (designated here). Narukila cordata (L.) Nieuwl. (≡ P. cordata L.).
Pontederaea Kuntze, Revis. Gen. Pl. 2: 718. 1891, orth. var.
Pontederas Hoffmanns., Verz. Pfl.: 137. 1824, orth. var.
Reussia
Endl., Gen. Pl.: 139. 1836. Type species (designated by
Unisema Raf. Med. Repos. 5: 352. 1808, nom. illeg. Type species. Unisema obtusifolia (Raf.) Raf. (≡ P. cordata L.).
Umsema Raf. Med. Repos. 5: 352 1808, orth. var.
Unisemma D.A.Godron, in Orbigny CVD, Dict. Univ. Hist. Nat.: 761. 1848, orth. var.
Herbs perennial or annual, aquatic to amphibious, erect-emergent or procumbent-emergent. Rhizome short and generally inconspicuous. Stems erect or trailing, spongy, unbranched to branching only at the base to branched. Sessile leaves early deciduous. Petiolate leaves distichously-alternate, evenly distributed along the stem or congested at the apex of the stem, emergent, ligule truncate, petioles not-inflated, blades cordate to broadly cordate, rarely elliptic to lanceolate or narrowly ovate. Main florescences (inflorescences) terminal, sessile or pedunculate; inflorescence leaf without an inflated leaf-sheath; basal bract flat; cincinni alternate, 1–3-flowered, sessile to shortly-pedunculate, internodes contracted. Flowers sessile, tristylous, zygomorphic, non-enantiostylous, perianth connate forming a tube, infundibuliform, revolute at post-anthesis, non-deliquescent and loosely enclosing the developing fruit, lobes 3 superior and 3 inferior, rarely 5 superior and 1 inferior, the central superior lobe with a nectar guide, consisting of 2 yellowish-green to green spots, generally surrounded by a dark purple to bluish-purple, rarely white blur, coiling or post-anthesis; stamens dimorphic, filaments free from each other, J-shaped, glandular-pubescent, anthers dorsifixed, rimose; ovary with 1 fertile locule, 1-ovulate, septal nectaries present, style glandular-pubescent or glabrous, stigma truncate or capitate or trilobate. Achene ovoid or pyriform; anthocarp hardened, ridged, ridges sinuate, toothed or echinate. Seeds curved narrowly ovoid or ovoid, testa smooth.
Pontederia subg. Pontederia. A–C habit: A dense population of P. parviflora Alexander B population of P. ovalis Mart. ex Schult. & Schult.f. C habit of P. rotundifolia L.f. D–E petiolate leaves: D blade of P. rotundifolia E blade of P. parviflora F–H inflorescences: F inflorescence of P. cordata L., showing flowers with two yellow nectar guides in the posterior perianth lobes G inflorescence of P. parviflora, showing flowers with a sole yellow nectar guide in the posterior perianth lobes H inflorescence of P. rotudifolia, showing a lilac-flowered form I oblique view of a flower of P. ovalis J–K fruits: J detail of the apex of the infructescence of P. ovalis, showing the anthocarp with sinuate ridges K detail of an achene of P. cordata, showing the toothed ridges. A by C. Willig & L. Nusbaumer B, I, J by M.O.O. Pellegrini C by L.O.A. Teixeira, D, H by R. Aguilar E by M.R. Engels F by Ashitaka-f Studio G by M.V. Lameiras and K by A. Haines.
Pontederia subg. Pontederia is circumscribed by us to comprise eight species. Our concept of P. subg. Pontederia is equivalent to the concept of Pontederia adopted by
Exclusively Neotropical.
1 | Rhizomes absent; stems elongated, trailing; leaves evenly distributed along the stem; anthocarp echinate; seeds straight, ovoid | 2 |
– | Rhizomes present, short; stems short, erect; leaves congested at the apex of the stem; anthocarp toothed or with sinuate ridges; seeds curved, narrowly ovoid | 4 |
2 | Petiolate leaf-blades with cordate to sagittate base; inflorescences 30–80-flowered, cincinni 2–3-flowered; flowers lilac or light to medium pink, rarely white, perianth lobes with a 3+3 arrangement | P. rotundifolia L.f. |
– | Petiolate leaf-blades with obtuse to cuneate base; inflorescences 2–15-flowered, cincinni 1-flowered; flowers light to medium blue, rarely white, perianth lobes with a 5+1 arrangement | 3 |
3 | Petiolate leaf-blades emergent, elliptic to narrowly ovate to ovate to rhomboid; inflorescences (6–)8–20-flowered | P. subovata (Seub.) Lowden |
– | Petiolate leaf-blades floating, linear-lanceolate to linear-elliptic to linear rhomboid; inflorescences 2–4(–5)-flowered | P. triflora (Endl. ex Seub.) G.Agostini et al. |
4 | Petioles green, blades with a thickened midvein; inflorescences and flowers covered with light yellow hairs, flowers homostylous, central superior lobe with 1 spot, anthers dark brown to black, style equal in length with the inferior stamens | P. parviflora Alexander |
– | Petioles red to vinaceous to purple, rarely green, blades lacking a thickened midvein; inflorescences and flower covered with hyaline hairs, flowers tristylous, central superior lobe with 2 spots, anthers yellow or greyish-blue to purple, style either shorter or longer than the inferior stamens | 5 |
5 | Basal bract deflexed, main axis glabrous; central superior lobe with 2 green spots, style glandular-pubescent, stigma trilobate; anthocarp with toothed ridges | P. cordata L. |
– | Basal bract upright, main axis velutine or sparsely to densely villose; central superior lobe with 2 yellow spots, style glabrous, stigma truncate; anthocarp with sinuate ridges | 6 |
6 | Petiolate leaf-blades elliptic to narrowly ovate to ovate to broadly ovate; cincinni 2–3-flowered | P. ovalis Mart. |
– | Petiolate leaf-blades sagittate to broadly sagittate or hastate to broadly hastate; cincinni 4–6-flowered | P. sagittata C.Presl |
Unisema cordata (L.) Farw., Pap. Michigan Acad. Sci. 3: 91. 1924.
Narukila
cordata
(L.) Nieuwl., Amer. Midl. Naturalist 3: 101. 1913. Lectotype (designated by
Pontederia lancifolia Muhl., Cat. Pl. Amer. Sept.: 34. 1813.
Unisema cordata fo. lancifolia (Muhl.) Farw., Pap. Michigan Acad. Sci. 3: 92. 1924.
Narukila cordata var. lancifolia (Muhl.) Nieuwl., Repert. Spec. Nov. Regni Veg. 12: 101. 1913.
Pontederia
cordata
var.
lancifolia
(Muhl.) Torr., Fl. N. Middle United States: 343. 1824. Lectotype (designated by
Widely distributed in North, Central and South America from Canada to Uruguay and the West Indies.
Pontederia cordata has always been the origin of much debate and taxonomical confusion in the genus. Most of the species currently accepted by us in Pontederias.l. have either been confused or compared with P. cordata, at some point. This can be demonstrated by how many of them have been treated either as synonyms or infraspecific taxa by different authors (
Pontederia lanceolata f. ovalis (Mart. ex Schult. & Schult.f.) A.Cast., Arch. Jard. Bot. Rio de Janeiro 15: 62. 1957.
Pontederia cordata var. ovalis (Mart. ex Schult. & Schult.f.) Solms, Monogr. Phan. 4: 533. 1883. Lectotype (designated here). BRAZIL. s.loc., fl., s.dat., C.F.P. Martius 14 (M barcode M0242238!).
Costa Rica, Guatemala, Honduras, Bolivia, Brazil (states of Bahia, Maranhão, Paraíba, Distrito Federal, Goiás, Mato Grosso, Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Rio Grande do Sul), Colombia, Paraguay and Uruguay.
When describing P. ovalis,
Pontederia ovalis has been considered by most authors and online databases as either a variety (
Pontederia cordata var. parviflora (Alexander) Schery, Ann. Missouri Bot. Gard. 31: 156. 1944. Lectotype (designated here). PANAMA. Camino del Boticario, near Chapo, fl., Oct 1911, H. Pittier 4556 (NY barcode NY00260019!: isolectotypes: NY barcode NY00260020!, US barcode US00091647!).
Panama, Venezuela, Colombia and Brazil (states of Tocantins, Alagoas, Ceará, Maranhão, Paraíba, Pernambuco, Piauí, Distrito Federal, Goiás, Mato Grosso do Sul, Mato Grosso, Minas Gerais and São Paulo).
Reussia
rotundifolia
(L.f.) A.Cast., Lilloa 25: 593. 1952. Lectotype (designated by
Mexico, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, French Guiana, Guyana, Suriname, Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina, Paraguay, Uruguay and Brazil (states of Amazonas, Pará, Rondônia, Roraima, Tocantins, Alagoas, Bahia, Maranhão, Paraíba, Pernambuco, Distrito Federal, Goiás, Mato Grosso do Sul, Mato Grosso, Minas Gerais, Rio de Janeiro, Paraná, Rio Grande do Sul and Santa Catarina).
Pontederia cordata f. sagittata (C.Presl) Solms, Monogr. Phan. 4: 533. 1883.
Pontederia var. sagittata (C.Presl) Schery, Ann. Missouri Bot. Gard. 31: 157. 1944. Holotype. MEXICO. s.loc., fl., fr., s.dat., T.P.X. Haenke s.n. (PRC barcode PRC450416!).
Mexico, Costa Rica, Guatemala, Honduras, Panama and Brazil (states of Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Rio Grande do Sul and Santa Catarina).
Pontederia sagittata is a poorly circumscribed taxon that is morphologically similar to P. cordata, due to the shape of the blade of their petiolate leaves. However, it is molecularly more closely related to P. ovalis, having in common the anthocarp with sinuate ridges. The disjunctive distribution of P. sagittata is probably related to misidentified specimens and/or the presence of cryptic species in what we currently accept as P. sagittatas.l. Great variation in petiolate leaf shape can be observed throughout its distribution, especially in Brazil. We believe that P. sagittata should be properly studied, using different approaches than traditional taxonomy, in order to solve this issue.
Reussia subovata (Seub.) Solms, Monogr. Phan. 4: 534. 1883.
Eichhornia
subovata
Seub., Fl. Bras. 3(1): 91. 1847. Lectotype (designated by
Venezuela, Guyana, Bolivia, Argentina, Paraguay and Brazil (states of Acre, Amazonas, Amapá, Pará, Tocantins, Bahia, Piauí, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo, Paraná, Rio Grande do Sul and Santa Catarina).
Reussia triflora Endl. ex Seub., Fl. Bras. 3(1): 96. 1847. Type (not found). BRAZIL. Pohl; Sellow (B?).
Colombia, Venezuela, Guyana, Bolivia, Argentina and Brazil (states of Roraima, Mato Grosso, Mato Grosso do Sul and Minas Gerais).
Due to the impossibility of finding the type specimen(s?) of Reussia triflora in any of the visited herbaria, we do not designate any types for this name at this point.
Pontederia triflora has been greatly confused with P. subovata, since its original description as R. triflora by
Pontederiaceae was one of the first families of flowering plants to be the focus of studies dealing with its phylogenetic history, based on morphological, molecular and combined data (
The authors would like to thank Reinaldo Aguilar, Ashitaka-f Studio, Michael Barritt, Philippe Birnbaum (from Dressler, S., Schmidt, M. & Zizka, G. 2014. African Plants - A Photo Guide. www.africanplants.senckenberg.de.), Cláudia P. Bove, Tomas C. Buruwate, Antônio S. Castro (from Flora do Ceará), Russell Cumming, Mathias R. Engels, André P. Fontana, Olivier Gaubert, Arthur Haines (New England Wild Flower Society, from www.gobotany.newenglandwild.org), Marcus Vinicius Lameiras, Herison Medeiros, Cerlin Ng, Louis Nusbaumer, Samuel S. de Oliveira, Alison & Steve Pearson (Arlie Beach), Pieter B. Pelser & Julie F. Barcelona [from Pelser, P.B., J.F. Barcelona & D.L. Nickrent (eds.). 2011 onwards. Co’s Digital Flora of the Philippines. www.philippineplants.org], Alex Popovkin, Kate Pritchard and Stephen A. Harris (Oxford University Herbarium), Luiz O.A. Teixeira, Steven R. Turner, Christian Willig (Nordesta Reforestation & Education) and Dinesh Valke, for the beautiful pictures of Pontederiaceae. The authors would also like to thank Peter Stevens and an anonymous reviewer for contributions and constructive criticism during the review of this manuscript. MOOP would like to thank CAPES for his current PhD scholarship, besides Fundação Flora de Apoio à Botânica and Smithsonian Institution for his REFLORA grant. RFA thanks CAPES for his postdoc fellowship. This study was carried out as part of the first author’s PhD degree in Botany at Programa de Pós-Graduação em Botânica, Instituto de Biociências, Universidade de São Paulo – USP.
List of morphological characters and coding
Morphological matrix