Entada Adans., Fam. Pl. 2: 318. 1763.

Figs 120, 121, 122, 123

Gigalobium P. Browne, Civ. Nat. Hist. Jamaica: 362. 1756, nom. rej. vs. Entada Adans.. Lectotype (designated by Panigrahi in Taxon 34: 714. 1985): Entada gigas (L.) Fawc. & Rendle [≡ Mimosa gigas L.]

Perima Raf., Sylva Tellur.: 118. 1838. Type: Perima odorata Raf., nom. illeg. [= Mimosa scandens L. (= Entada phaseoloides (L.) Merr.)]

Strepsilobus Raf., Sylva Tellur.: 117. 1838. Type: Strepsilobus scandens (L.) Raf. [≡ Mimosa scandens L. (= Entada phaseoloides (L.) Merr.)]

Elephantorrhiza Benth., J. Bot. (Hooker) 4: 344. 1841. Type: Elephantorrhiza burchellii Benth., nom. illeg. [≡ Acacia elephantorrhiza Burch. ex DC., nom. illeg. (= Entada elephantina (Burch.) S.A. O’Donnell & G.P. Lewis)]

Pusaetha L. ex Kuntze, Revis. Gen. Pl. 1: 204. 1891. Type: Pusaetha scandens (L.) Kuntze [≡ Mimosa scandens L. (= Entada phaseoloides (L.) Merr.)]

Entadopsis Britton, N. Amer. Fl. 23: 191. 1928. Type: Entadopsis polystachya (L.) Britton [≡ Mimosa polystachya L. (≡ Entada polystachya (L.) DC.)]

Type.

Entada monostachya DC., nom. illeg. [≡ Mimosa entada L. (≡ Entada rheedei Spreng. subsp. rheedei)]

Description.

Lianas (Fig. 120A), scandent shrubs (Fig. 120C), small trees (Fig. 120E) or geoxylic suffrutices (Fig. 120F), unarmed except for spinescent stipules in E. spinescens . Stipules inconspicuous, setaceous, or in E. spinescens rigid, subconical, divaricate, spinescent, 1.5-3.5 mm long. Leaves (Fig. 121A-D) bipinnate; primary and secondary axes either eglandular or, in some Madagascan species, with extrafloral nectaries and at least in E. phaseoloides, with unusual ‘pit’ nectaries on stems at nodes adjacent to petiole; rachis in lianescent taxa terminating in a bifurcating tendril (modified terminal pinnae pair) (Fig. 121A); pinnae 1-many pairs per leaf; leaflets 1-many pairs per pinna, lamina often asymmetric and apically mucronate or emarginate. Inflorescence (Fig. 121G, H) spiciform racemes or spikes, axillary to supra-axillary, solitary or clustered, sometimes into terminal panicles. Flowers (Fig. 121G, H) sessile to shortly pedicellate, 5-merous, staminate or bisexual, cream-coloured, yellow, green, red or purple; calyx gamosepalous, campanulate, the fused sepals distinctly toothed or not; petals free to basally connate, adnate basally with the stamens and a perigynous disc forming a stemonozone; stamens 10, fertile, free or basally united, anthers usually with a caducous spheroidal, apical, sessile to stipitate gland; pollen tricolporate, tectum finely reticulate to striate, infratectum columellate, dispersed as monads; ovary glabrous and multi-ovulate, style tapering to a tubular to rarely cupuliform stigma. Fruit (Fig. 122A-I) a craspedium, torulose or not, compressed to flattened, straight to curved to rarely spirally twisted, sometimes gigantic (up to 2 m long in taxa with sea-drifted seeds); epicarp woody to thinly coriaceous; endocarp woody to parchment-like; splitting along transverse septa into one-seeded segments upon ripening or valvately dehiscent, the entire valve breaking away from the replum and the epicarp also separating from the endocarp. Seeds (Fig. 122M-P) globular to elliptic, usually laterally compressed, longest axis up to 6 cm in large-fruited taxa, dark brown, smooth, with or without areole, pleurogram (when present) usually open.

Chromosome number.

2 n = 28 (Santos et al. 2012).

Included species and geographic distribution.

Forty species, widespread, primarily tropical, but reaching subtropical latitudes in southern Africa and eastern Asia (Fig. 123). Twenty-nine species in sub-Saharan Africa (including six species in Madagascar, three of which are endemic); nine species in Asia; four species in the Americas. Three species with large fruits and seeds are very widely distributed by ocean currents ( E. rheedei circum-Indian Ocean, South East Asia and northern Australia; E. gigas in Central and northern South America to west and central Africa; E. phaseoloides from East and South East Asia to north-east Australia and south-west Pacific Ocean islands).

Ecology.

Frequently in riparian and littoral vegetation including at the landward fringes of mangroves, though also in savanna, open woodland, thickets and open, dry to dense, humid forest, often on sandy substrates.

Etymology.

Likely from the indigenous name for the plant in Malabar, India (Luckow 2005); the alternative derivation of the name given in the same publication seems less likely and is omitted here.

Human uses.

Seeds and bark of several species are ground and used in traditional medicines, as soap, and as fish poison; leaves and detoxified seeds are eaten as famine food (Lungu 1995). Tannins in roots of species formerly included in Elephantorrhiza are used in tanning leather and as dye (Grobler 2012). Various species are used as fodder; for fibre; for firewood and charcoal; large, sea-drifted seeds are used in jewellery (Luckow 2005).

Notes.

The study of Luckow et al. (2003) was the first to suggest that Elephantorrhiza might be phylogenetically nested within Entada, a relationship that has subsequently received robust molecular support (LPWG 2017; Koenen et al. 2020a; Ringelberg et al. 2022). Based on these results, all eight species previously placed in Elephantorrhiza were subsumed within Entada by O’Donnell et al. (2022).

Taxonomic references.

Barneby (1996); Braga et al. (2016); Brenan (1959, 1966, 1970); Cowan (1998); Grobler (2012); Lungu (1995); Nielsen (1981a, 1992); O’Donnell et al. (2022); Ohashi et al. (2010); Ross (1974, 1975a); Tateishi et al. (2008); Villiers (2002); Wu and Nielsen (2010).