Re-circumscription of the mimosoid genus Entada including new combinations for all species of the phylogenetically nested Elephantorrhiza (Leguminosae, Caesalpinioideae, mimosoid clade) Author O'Donnell, Shawn A. https://orcid.org/0000-0003-0731-7425 Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE 1 8 ST, UK shawn.odonnell@cantab.net Author Ringelberg, Jens J. https://orcid.org/0000-0003-0567-5210 Department of Systematic and Evolutionary Botany, University of Zurich, 8008 Zurich, Switzerland Author Lewis, Gwilym P. https://orcid.org/0000-0003-2599-4577 Accelerated Taxonomy Department, Royal Botanic Gardens, Kew, Richmond, TW 9 3 AE, UK text PhytoKeys 2022 2022-08-22 205 99 145 http://dx.doi.org/10.3897/phytokeys.205.76790 journal article http://dx.doi.org/10.3897/phytokeys.205.76790 1314-2003-205-99 4024A478048757B197E5CF8734331A9E Entada tonkinensis Gagnep., Notul. Syst. (Paris) 2: 60. 1911. ≡ Entada phaseoloides subsp. tonkinensis (Gagnep.) H. Ohashi, Taiwania 55: 50. 2010. Type . VIETNAM . Banton Valley , near Tu-vu, B. Balansa 2130 ( holotype : P [P02436139, P02436140]) . Description. Robust liana, stems often flattened and spirally twisted, base up to 60 cm in diameter. Leaves : petiole 1.5-4 cm long, rachis 3-6.5 cm long, terminating in a bifurcating tendril; pinnae (1-)2 pairs per leaf, 10-22 cm long, proximal pinnae with 2 opposite pairs of leaflets, distal pinnae with 2-3 opposite pairs of leaflets, increasing in size distally; leaflets 5-12 x 2.5-6 cm, chartaceous, obliquely elliptic to obovate-elliptic, asymmetrical, apex acute to obtuse. Inflorescence : a spike, 9-25 cm long, axillary, solitary or several spikes from a short shoot; peduncle glabrous; rachis puberulous. Flowers : sessile to sub-sessile, distylous; short-styled flowers on proximal half of spike, long-styled flowers on distal half of spike; calyx cupular, glabrous, 1.2-2 mm long; petals pale green with a reddish base, 3-3.2 mm long; stamen filaments 5.5-7 mm long, white turning yellow; ovaries of long-styled flowers with 12-18 ovules. Fruit : a gigantic torulose craspedium, 50-150 x 9-12 cm, laterally compressed, straight to slightly curved, 9-16-seeded, with transverse septa between seeds dividing the fruit into one-seeded segments which, upon ripening, fall from the persistent replum; segments 6.5-7.5 cm long; endocarp chartaceous. Seeds : subcircular, compressed with a rounded margin, 5.2-7.4 x 4.7-5.5 x 1.6-2.3 cm, hard, blackish-purple, pleurogram lacking. Distribution. Subtropical Japan (Ryukyu Islands), Taiwan (north and central), southern China, northern Vietnam. Habitat and ecology. Inland evergreen forests, especially riparian, from low to mid-elevations.