Entada tonkinensis Gagnep., Notul. Syst. (Paris) 2: 60. 1911.

O'Donnell, Shawn A., Ringelberg, Jens J. & Lewis, Gwilym P., 2022, Re-circumscription of the mimosoid genus Entada including new combinations for all species of the phylogenetically nested Elephantorrhiza (Leguminosae, Caesalpinioideae, mimosoid clade), PhytoKeys 205, pp. 99-145 : 99

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 × 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 × 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 × 4.7-5.5 × 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.