| General Information |
| Distribution | Widespread, tropical and subtropical weed.In the Hawaiian Islands,
naturalized on
Kure, Kaua`i, O`ahu, Maui, Kaho`olawe.
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Habit
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Taprooted annual herbs 1.5-8(-20) dm tall, puberulent or subglabrous; stems often purplish, divaricately branched.
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Leaves
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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.
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Flowers
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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.
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Fruit
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Achenes 2-2.6 mm long.
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Chromosomes
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2n = 36
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