General Information |
Distribution | Native from southern United States to Argentina and the West Indies, widely naturalized in the Paleotropics.In the Hawaiian Islands,
naturalized on
Kure, Midway, French Frigate Shoals, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.
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Habit
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Glabrous annual herbs; stems erect or ascending, 0.1-0.5 m long.
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Leaves
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Leaves oblong to oblong-lanceolate, 6-35 mm long, 4-12 mm wide, conspicuously veined, margins serrate, apex rounded or obtuse, base obtuse to cordate, petioles 1-1.5 mm long, stipules connate, deltate, membranous, 1-2 mm long, sometimes ciliate on the inner edge.
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Flowers
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Cyathia in lateral, terminal, nearly leafless, few-flowered cymes; involucre 0.5-1 mm high, glabrous, glands 5, elliptic to suborbicular, 0.05-0.2 mm long, appendages white to pink, rotund and usually ca. 3 times as wide as the larger glands, sometimes absent; male flowers 2-20 per cyathium.
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Fruit
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Capsules subglobose, 3-angled, the angles rounded, 1-1.5 mm long, 1.2-1.5 mm in diameter, usually broadest at middle, glabrous.
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Seeds
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Seeds brown, ovoid, obtusely 4-angled, ca. 0.8 mm long, the faces wrinkled.
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Chromosomes
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2n = 16, 28, 56
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