Coatbuttons

Tridax procumbens is a sprawling annual or short-lived perennial herb of the Asteraceae family with prostrate to decumbent, much-branched stems 20-60 cm long that root at the lower nodes and are clothed in spreading whitish hairs. The opposite leaves are simple, lanceolate to ovate-lanceolate, 2-7 cm long and 1-3 cm wide, with coarsely serrate or pinnately lobed margins, an acute apex and a tapering base; both surfaces are roughly hairy. Solitary terminal flower heads 8-15 mm wide are borne on slender peduncles 10-30 cm long held well above the foliage. Each head has 4-8 pale yellow to creamy-white outer ray florets with three-lobed strap-shaped corollas and a dense disc of yellow tubular florets surrounded by an involucre of two rows of green hairy bracts. The fruit is a hard, blackish, densely hairy cypsela 2-3 mm long crowned by a feathery off-white pappus of plumose bristles 5-7 mm long that disperses readily in wind. Native to tropical America, it is now a near-cosmopolitan weed of roadsides, lawns, fields and waste ground throughout the tropics and subtropics.