Bidens kirkii Sherff

Branched perennial herb, up to 1 m high, glabrous. Stem irregularly branched, terete or somewhat tetragonal, several from a thick rhizome. Leaves ovate in outline, deeply pinnately or sub-bipinnately 3-7-lobed, up to 10 cm long, petiolate; petiole up to 3.5 cm long; leaf segments simple or 3-partite, glabrous, linear or narrowly elliptic rather thick and coriaceous; apex acute to acuminate, indurate; margin entire, subrevolute. Capitula erect, broadly funnel-shaped or hemispheric, 1-2(-3) at the ends of terminal peduncles 3-4.5 x 0.7-0.9 cm at anthesis; peduncle glabrous, up to 16 cm long; receptacle glabrous or pubescent. Phyllaries differentiated in shape, size and colour. Outer phyllaries green, 4-8, linear, or narrowly elliptic, 4-14 mm long, sparsely pubescent at base; apex acute or obtuse, callose-thickened. Inner phyllaries greyish orange with scarious margin, c. 8, oblong, glabrous except the puberulous apex, 6-10 mm long. Ray florets yellow, 5-8; ovary aristate, neuter; rays narrowly elliptic-obovate with 13-20 dark brown striae, 1.5-3 cm long; apex entire or minutely 3-fid; tube glabrous or sparsely pubescent. Paleae thin, c. 7-10 cm long, linear, obtuse. Disc florets yellow; corolla 5-lobed, narrowly funnel-shaped above, glabrous. Achenes black or dark brown, linear-oblong, obcompressed, hispidulous or glabrescent with a few short bristles near the apex and margins, 6-7 x 1.2-1.6 mm; apex with a ring of short erect, irregularly-sized bristles, bi-aristate; aristae entire except for the few bristles at base and a single antrorsely or retrorsely set one at apex, c. 2 mm long.