Crotalaria involutifolia Polhill

Suberect delicate annual, up to 1–5 dm. tall.. Stem very slender, laxly branched, sparsely appressed puberulous, glabrescent.. Leaves sessile, simple; blade linear to linear-oblanceolate, up to 12–38 mm. long, 0·5–2 mm. wide, acute or bluntly pointed, apiculate, narrowed to the base, with the margins mostly inrolled at least to some extent, glabrous or sparsely puberulous above, sparsely appressed puberulous and often glabrescent beneath.. Stipules filiform, minute or apparently absent.. Racemes slenderly pedunculate, up to 4–12 cm. long, with ± 2–8 widely spaced flowers on the slender rhachis; bracts filiform, ± 0·5–1 mm. long; bracteoles inserted at the base of the calyx, minute.. Calyx 2·5–3·5 mm. long, puberulous; lobes acuminately triangular, usually a little longer than the tube.. Standard obovate-orbicular, yellow, usually veined reddish-brown and glabrous outside; wings a little shorter to a little longer than the keel; keel rather abruptly rounded below the middle, with a short straight or slightly incurved acute untwisted beak, 3·5–6·5 mm. long.. Pod subsessile, narrowly cylindrical, 9–14 mm. long, 2–2·5 mm. across, pubescent, ultimately glabrescent, ± 18–22-seeded.. Seeds oblique-cordiform, ± 1–1·2 mm. long, smooth, brown.