A new generic circumscription of Hydrochorea (Leguminosae, Caesalpinioideae, mimosoid clade) with an amphi-Atlantic distribution Author Vinicius Batista Soares, Marcos https://orcid.org/0000-0003-2660-1771 Universidade Federal do Rio Grande do Sul, Programa de Pos-Graduacao em Botanica, Av. Bento Goncalves 9500, Bloco IV, Predio 43433, 91501 - 970, Porto Alegre, Rio Grande do Sul, Brazil Author Mathieu Koenen, Erik Jozef https://orcid.org/0000-0002-4825-4339 Rua dos Bandeirantes 1020, Caranazal, 68040 - 329, Santarem, Para, Brazil erikk_botany@gmx.com Author Ricardo Vieira Iganci, Joao https://orcid.org/0000-0002-5740-3666 Universidade Federal do Rio Grande do Sul, Programa de Pos-Graduacao em Botanica, Av. Bento Goncalves 9500, Bloco IV, Predio 43433, 91501 - 970, Porto Alegre, Rio Grande do Sul, Brazil & Evolutionary Biology & Ecology, Universite Libre de Bruxelles, Faculte des Sciences, Campus du Solbosch - CP 160 / 12, Avenue F. D. Roosevelt 50, 1050 Bruxelles, Belgium Author Morim, Marli Pires Instituto de Biologia, Universidade Federal de Pelotas, Campus Universitario Capao do Leao, Travessa Andre Dreyfus s / n, 96010 - 900, Capao do Leao, Rio Grande do Sul, Brazil text PhytoKeys 2022 2022-08-22 205 401 437 http://dx.doi.org/10.3897/phytokeys.205.82775 journal article http://dx.doi.org/10.3897/phytokeys.205.82775 1314-2003-205-401 71D1ED9CE6165A94A2A330D2DA4D6DD9 5. Hydrochorea marginata (Spruce ex Benth.) Barneby & J.W. Grimes, Mem. New York Bot. Gard. 74(1): 29. 1996. Figs 2A, D , 6 Basionym. Pithecellobium [as Pithecolobium ] Pithecolobium marginatum Spruce ex Benth., Trans. Linn. Soc. London 30: 586. 1875. Type material. Brazil, Barra, by a stream [Prov. Rio Negro], Spruce 1658 (lectotype, designated by Barneby and Grimes 1996 , p. 31: K [K000528011]!; isolectotypes: E [E00313848] digital image!, F [V0058733F] digital image!], G [G275450] digital image!, P [P03094432] digital image!, P [P03094430] digital image!). Figure 6. Hydrochorea marginata (Spruce ex Benth.) Barneby & J.W. Grimes A branch with inflorescences B-D extra-floral nectaries E peripheral flower bud F peripheral flower G terminal flower bud H terminal flower I leaflet. A-D, F, H, I from A. Carlos et al. 066 E, G from C. Ferreira et al. 7260 . Illustration by Alex Pinheiro. Distribution and habitat. Brazil and Venezuela. Hydrochorea marginata occurs in Amazonia, in flooded areas and along riverbanks and lake shores. Notes. Barneby and Grimes (1996) considered H. marginata to comprise three varieties, H. marginata var. panurensis (Benth.) Barneby & J.W. Grimes, H. marginata var. scheryi Barneby & J.W. Grimes, and Hydrochorea marginata var. marginata . Hydrochorea marginata var. panurensis is recognized at the species level in this treatment, and H. marginata var. scheryi is placed as a synonym of H. panurensis because we identified no morphological diagnostic characters that support them as independent taxa. Both these taxonomic decisions are discussed under H. panurenis . Selected specimens examined. Brazil : Amazonas , Rio Negro between Moreira and Rio Ariraha , 13 October 1971 , G.T. Prance 15206 (NY) .