(Spreng.) C. Mohr
[Oedera trinervia Spreng.]
(nat)
Taprooted annual herbs 1.5-8(-20) dm tall, puberulent or subglabrous; stems often purplish, divaricately branched. Leaves lanceolate, oblanceolate to elliptic or narrowly ovate, 3-15 cm long, (0.7-)1-4 cm wide, distinctly 3-nerved from base, margins subentire to serrate-dentate, petioles of principal leaves 1-2 cm long, petiole bases nearly connate, upper leaves sessile and usually connate. Heads with a single floret, aggregated into secondary head-like clusters ca. 1 cm in diameter, the common receptacle thus formed with scattered bristles ca. 1/2 as long to as long as primary heads, secondary heads subtended by a few leafy bracts, heads radiate or discoid, radiate heads usually peripheral in secondary heads, the central ones usually discoid; involucre of primary heads of 1-2 bracts, 3-4.5 mm long; rays pale yellow or whitish, 0.5-1 mm long; disk corollas 2-2.5 mm long; pappus absent. Achenes 2-2.6 mm long. [2n = 36.] A widespread tropical and subtropical weed; in Hawaii sparingly naturalized in strand vegetation and coastal sites from Barber’s Point to Sand Island and at Koko Head, 0‘ahu. Also reported, but not vouchered, from ‘Ewa Plains, especially on bulldozed coralline limestone areas. First collected in 1937 (Egler 37-232, BISH).—Plate 26.