Taxonomic updates in Dolichandra Cham. (Bignonieae, Bignoniaceae)

Abstract Dolichandra is a genus of lianas found in dry and wet Neotropical forests. The genus currently includes eight species and is well characterized by molecular and morphological synapomorphies. Here, Macfadyena hispida (DC.) Seemann is removed from synonomy with Dolichandra uncata (Andrews) L.G. Lohmann based on the presence of the hispid indument, vinaceus ovary, long fruits, and winged seeds. The combination Dolichandra hispida (DC.) L.H. Fonseca & L.G. Lohmann, comb. nov. is proposed, increasing the number of accepted species of Dolichandra to nine. A taxonomic key for all species of Dolichandra is presented.


Introduction
Dolichandra Cham. is a genus of lianas that belongs to the tribe Bignonieae, in the plant family Bignoniaceae Lohmann and Taylor 2014). Th e family comprises ca. 80 genera and 840 species of trees, lianas and shrubs (Lohmann and Ulloa 2006, onwards), representing an important component of Neotropical forests and dry areas. Th e tribe Bignonieae includes 21 genera and 393 species of lianas and is centered in Brazil (Lohmann and Taylor 2014).
Th e current circumscription of Dolichandra is based on molecular phylogenetic data  and morphological synapomorphies (Lohmann and Taylor 2014). In this circumscription, the genus is composed of eight species (Lohmann and Taylor 2014), one of which was previously included in Dolichandra, three in Macfadyena DC., one in Melloa Bureau, and three in Parabignonia Bureau ex K. Schum (Gentry 1973a(Gentry , 1973b. Under the new circumscription, Dolichandra is characterized by unique multiple dissected phloem wedges, trifi d and uncinate tendrils, fruits with four lines of dehiscence, a dimorphic growth form, a large and membranaceous calyx, and colpate pollen with a psilate exine (Gentry 1973a(Gentry , 1973bGentry and Tomb 1979;Lohmann and Taylor 2014).
Th e genus is distributed in wet and dry Neotropical forests, from Mexico to northern Argentina (Gentry 1973a(Gentry , 1973bLohmann and Taylor 2014), being a conspicuous component of seasonally dry forests. Th e geographic distribution of Dolichandra is centered in southern Brazil, northern Argentina and Paraguay, where up to seven species are found. Th e geographic distribution of members of Dolichandra is highly variable, with species found throughout the Neotropics, like the ubiquitous D. unguiscati (L.) L.G.Lohmann, and species with restricted distributions such as D. dentata (K. Schum.) L.G.Lohmann, found in riverbanks of the Uruguay river basin (Lohmann and Taylor 2014).
Dolichandra cynanchoides (cham.) L.G.Lohmann is cultivated as ornamental in Argentina (García 1992) and D. unguis-cati in the USA (Gentry 1982). Dolichandra unguis-cati is also an invasive in some countries, like Australia and South Africa (Sparks 1999;Dhileepan et al. 2007). Attempts to reduce population size and control the invasiveness of D. unguis-cati are underway in both countries (Sparks 1999;Dhileepan et al. 2007).
During phylogenic and taxonomic studies of Dolichandra, it became clear that Macfadyena hispida (DC.) Seem. is morphologically distinct from D. uncata (Andrews) L.G.Lohmann and should be recognized as a separate taxon. We here present the necessary new combination. We also provide a taxonomic key for the genus, thus facilitating the identifi cation of the species.
Nomenclatural notes. A single specimen was cited by Sonder for Spathodea mollis labeled 292 in Regnell's fi rst series of collections from Brazil. Four specimens labeled as Regnell I-292 were located, one at K [000449792], two at BR [876279] [876378] and one at MO [2229711]. Th e best quality material is selected here as lectotype.
Taxonomic notes. Dolichandra hispida is easily diff erentiated from all other species of Dolichandra by the unique hispid indument found on the vegetative and repro-ductive portions of this species, as well as the presence of a vinaceus ovary. Dolichandra hispida has been treated as a synonym of D. uncata since Gentry (1973a). However, the diff erences in indument (hispid vs. glabrous to puberulous), ovary color (vinaceus in D. hispida vs. green in D. uncata), and seed wing morphology (hyaline in D. hispida vs. woody in D. uncata) are clear, making the separation of these two species necessary. In addition, the diff erence in fruit length is also striking, with fruits being much longer in D. hispida (77-125.8 cm) than in D. uncata (9.2-38.5 cm). In fact, D. hispida presents one of the longest fruits of Bignoniaceae, and possibly one of longest capsules within the Angiosperms (Table 1).
Dolichandra uncata occurs predominantly in riverbanks, swamps and mangroves, presenting seeds that are corky and supposedly adapted for water dispersal (Gentry 1973b). On the other hand, D. hispida is more common in non-fl ooded areas, presenting seeds adapted to wind dispersal.
Distribution. Dolichandra hispida occurs in southern, southwestern and central Brazil, Paraguay and Bolivia, whereas D. uncata has its northern limit in Mexico and southern limit in Argentina and Uruguay (Fig. 2).
Phenology. Th is species was collected in fl ower in September, October, November, December and January and in fruit in September, November, December, January and February.
Conservation status. Dolichandra hispida is here considered as Least Concern [LC] according to IUCN criteria (IUCN 2012; IUCN Standards and Petitions Subcommittee 2014). Th e extent of occurrence estimated for the species is 2,209,625.833 km 2 and the estimated area of occupancy is 875.000 km 2 (cell width of 5 km). Th erefore this classifi cation was established based on the wide distribution of the taxon, since no population data is available.