Flora of the Hawaiian Islands
Dicotyledon Literature for Tridax procumbens
Wagner et al., 1990, 1999; Lorence & Wagner, 2020.
   Asteraceae -- The Sunflower Family Bibliography
      Tridax procumbens

Common name(s): coat buttons
General Information
DistributionApparently native only from Mexico, Central America, Venezuela, Colombia, Peru, and Bolivia, but now widespread throughout tropical and subtropical regions of the world.In the Hawaiian Islands, naturalized on Midway, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Taprooted, perennial herb; stems ascending to procumbent, often rooting at the nodes, 1.5‒4 dm long, sparsely to densely hirsute.
Leaves short-petiolate; blade ovate to lanceolate, 2‒7(‒12) cm long, 1‒4(‒6) cm wide, both surfaces sparsely to densely hirsute and often rough to the touch, 3-lobed, margin undulate; petiole 0.4‒3 cm long.
Heads campanulate, solitary on long peduncle (7‒)10‒18(‒20) cm long; involucral bracts 3.5‒6.5(‒8) mm long; ray florets 3‒6 per head, rays white, rarely pale yellow, 2.5‒4(‒5) mm long; disk corollas pale yellow, 5‒6.5(‒7) mm long; pappus of ca. 20 plumose bristles unequal in length, that of ray florets reduced.
Achenes black, cylindrical to narrowly obconical, 2‒2.5 mm long, densely pilose.
2n = 36
Nancy Khan