Flora of the Hawaiian Islands
Dicotyledon Literature for Flaveria trinervia
Wagner et al., 1990, 1999.
   Asteraceae -- The Sunflower Family Bibliography
      Flaveria trinervia
General Information
DistributionWidespread, tropical and subtropical weed.In the Hawaiian Islands, naturalized on Kure, Kaua`i, O`ahu, Moloka`i, Maui, Kaho`olawe.

Asteraceae - Flaveria trinervia Asteraceae - Flaveria trinervia















Habit
Taprooted annual herbs 1.5-8(-20) dm tall, puberulent or subglabrous; stems often purplish, divaricately branched.
Leaves
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.
Flowers
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.
Fruit
Achenes 2-2.6 mm long.
Chromosomes
2n = 36