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216. Sigesbeckia Linnaeus, Sp. Pl. 2: 900. 1753.
豨莶属 xi xian shu
Herbs, annual. Leaves opposite, petiolate, densely pubescent. Synflorescence of small terminal and axillary usually many-headed corymbs. Capitula pedunculate; involucre 2-seriate, campanulate; outer phyllaries 5, longer than inner, linear-spatulate, divaricate, with thick glandular hairs; receptacle flat with scarious paleae, enveloping achenes. Corollas yellow, marginal florets uniseriate, shortly limbed, female; disk florets tubular, bisexual. Achenes elongate-obovate, 4-angled, apex truncate; pappus absent. x = 15.
About four species: tropical and subtropical areas; three species in China.
See Humbles, Ci. Naturaleza Ci. Nat. 13: 2-19. 1972.
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| 1 |
Branches forked in upper part; leaves papery, irregularly lobulate. |
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1 S. orientalis |
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Branches not forked; leaves thinly membranous, usually toothed |
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(2) |
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| 2 (1) |
Stems and both surfaces of leaves uniformly soft pubescent; peduncle not glandular; achenes ca. 2 mm. |
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2 S. glabrescens |
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Stems and lower surfaces of leaves densely white pubescent; peduncle usually glandular pilose; achenes 2.5-3.5 mm. |
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3 S. pubescens |
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Lower Taxa
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