Literature for Bidens forbesii Wagner et al., 1990, 1999. Literature for Bidens forbesii subsp. forbesii Wagner et al., 1990, 1999. Literature for Bidens forbesii subsp. kahiliensis Wagner et al., 1990, 1999.
Asteraceae -- The Sunflower Family	Bibliography
Bidens forbesii

General Information
Distribution
Habit	Erect, suffrutescent perennial herbs 0.7-2 m tall, with horizontal to ascending lateral branches.
Leaves	Leaves pinnately compound or some simple, semisucculent to coriaceous, usually 11-36 cm long including petiole, leaflets (1-)3-7, ovate to ovate-lanceolate, usually 3.5-15 cm long, 2-7.5 cm wide, glabrous, margins serrate.
Flowers	Heads more than 50 in open, compound cymes terminating lateral branches only, 2-2.5 cm in diameter including ray florets, peduncles (0.2-)1-2.5 cm long, glabrous; outer involucral bracts 1.5-3.5 mm long, the inner ones distinct; ray florets 4-5 per head, sterile, rays yellow, 8-13 mm long, 3-6 mm wide, often smaller on female plants; disk florets 10-20 per head, perfect or female (and then plants gynodioecious), corollas yellow; pappus of minute awns or absent.
Fruit	Achenes black, straight, curved, or twisted ca. 1 revolution, wingless, 7-14(-16) mm long, 0.5-1.25 mm wide, usually conspicuously long-tapered apically, tapering to 0.3-0.75 mm wide below apex, setose near base and sometimes also above.
Chromosomes	[2n = 72*; subsp. forbesii.]