DistributionNative to tropical Asia; widely naturalized. In the Hawaiian Islands, naturalized on Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Habit

Erect or decumbent annual herbs (5-)15-30(-150) cm tall; stems finely striate, tomentulose with T-shaped hairs, sometimes glabrate with age.

Leaves

Leaves scattered along the stem, ovate, ovate-rhombic, or lanceolate, blade usually 2-5 cm long, 1.5-2.5 cm wide, upper surface pubescent with T-shaped hairs, lower surface pubescent and glandular punctate, margins remotely toothed; petiole ca. 1.5-2.5 cm long.

Flowers

Heads with 12-16 florets; involucre campanulate, 4-8 mm high, the bracts imbricate in 3-4 series, 3-5.5 mm long, apex purplish; corollas lavender to purple, 2.5-6 mm long; pappus whitish, inner bristles 3.5-4 mm long, deciduous, outer bristles ca. 0.2 mm long, persistent.

Fruit

Achenes rounded, nearly ribless, ca. 1.5 mm long.