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6. Sida Linnaeus, Sp. Pl. 2: 683. 1753.
黄花稔属 huang hua ren shu
Herbs perennial or annual, subshrubs or shrubs, to 2 m, most parts with stellate, simple and/or glandular hairs. Leaves simple; stipules threadlike to narrowly lanceolate; leaf blade entire (sometimes lobed), margin usually dentate, without foliar nectaries. Flowers solitary or paired, axillary or subterminal, often in axillary or terminal racemes or panicles, rarely in umbels or glomerules. Epicalyx absent. Calyx campanulate or cup-shaped, 5-lobed, often 10-ribbed basally and plicate in bud. Corolla mostly yellow, rarely white or ± orange [or rose or purplish], sometimes with a dark center. Petals 5, free, basally connate. Filament tube pubescent or glabrous, with many anthers at apex. Ovary 5-10-loculed; ovules 1 per locule, pendulous; style branches as many as carpels; stigma capitate. Schizocarp ± disk-shaped or globose; mericarps (4-)5-10(-14), sculptured or smooth, sometimes partly membranous, mostly beaked, often with 1 or 2 apical awns, often minutely stellate puberulent, dehiscent or indehiscent. Seeds 1 per mericarp, smooth, glabrous except sometimes for minute hairs around hilum.
Between 100 to 150 species: Africa, Asia, Australia, North and South America, Pacific islands; ca. 2/3 of the species American; 14 species (six endemic) in China.
Many species of this genus are used as fiber sources. Some species are widespread ruderals with sporadic distributions. Material with fully mature fruits is needed for reliable determinations. Studies of African material have demonstrated that there are superficially similar species that differ most obviously in details of mericarp morphology, and detailed studies have led to the recognition of more, rather than fewer, taxa. More information is needed on variation within populations, particularly in mericarp morphology, to assess the status of the awnless species of Sida, as there are indications that awned and awnless mericarps can occur on the same plant, thereby suggesting a possible reduction in species numbers. Sida cavaleriei H. Léveillé is a synonym of Alectra arvensis (Bentham) Merrill in the Scrophulariaceae (see Fl. China 18: 86. 1998).
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| 1 |
Calyx adaxially with long simple hairs at least along veins; mericarps smooth, thin-walled, not dehiscent |
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(2) |
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Calyx adaxially stellate pubescent or glabrous, sometimes with ciliate margins; mericarps smooth, vertically grooved or reticulately wrinkled, sometimes dehiscent |
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(4) |
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| 2 (1) |
Herbs erect; pedicel 2-6(-15) mm; live plants sticky, with inconspicuous glandular hairs as well as stellate and/or simple hairs. |
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11 S. mysorensis |
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Herbs or subshrubs procumbent; pedicel (1-)2-4 cm; plants not sticky, without glandular hairs |
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(3) |
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| 3 (2) |
Stems both stellate puberulant and simple pilose, never rooting at nodes; mericarps without distinct awns. |
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12 S. cordata |
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Stems subglabrous or stellate puberulent, rooting at nodes; mericarps with 2 short awns. |
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13 S. javensis |
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| 4 (1) |
Mericarp awns conspicuous, 3-8 mm, retrorsely barbed |
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(5) |
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Mericarp awns absent or less than 2 mm, hairs if present ± spreading |
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(6) |
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| 5 (4) |
Leaf blade 5-10 cm; corolla 2-3.5 cm in diam.; filament tube glabrous. |
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7 S. subcordata |
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Leaf blade 1-5 cm; corolla less than 1.5 cm in diam.; filament tube with long hairs. |
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8 S. cordifolia |
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| 6 (4) |
Flowers fascicled or in umbel-like or subpaniculate inflorescences |
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(7) |
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Flowers usually solitary, axillary or subterminal, sometimes on racemelike axillary shoots |
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(8) |
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| 7 (6) |
Leaf blade ovate, base cordate. |
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9 S. cordifolioides |
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Leaf blade obovate, broadly elliptic, or orbicular, base rounded or obtuse. |
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10 S. yunnanensis |
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| 8 (6) |
Leaves distichous; leaf blade base rounded or obtuse; stipules unequal, one filiform with a single vein, the other linear-lanceolate with 2 or more veins; calyx and mericarps often glabrous. |
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3 S. acuta |
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Leaves spiral; leaf blade base cuneate to minutely rounded; stipules equal; calyx hairy; mericarps often with apex ± puberulent |
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(9) |
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| 9 (8) |
Mericarps without awns |
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(10) |
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Mericarps with awns |
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(11) |
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| 10 (9) |
Leaf blade obovate, oblong, or suborbicular, 0.5-2 cm; petiole 2-4 mm. |
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1 S. chinensis |
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Leaf blade ovate to linear-lanceolate, 2-7 cm; petiole 8-20 mm. |
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2 S. orientalis |
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| 11 (9) |
Petiole 5-11 mm |
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(12) |
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Petiole 3-5(-8) mm |
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(13) |
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| 12 (11) |
Leaf margin irregularly sharply dentate to double dentate; calyx sparsely stellate pilose. |
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4 S. szechuensis |
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Leaf margin entire near base, otherwise obtusely denticulate; calyx densely stellate pubescent. |
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14 S. quinquevalvacea |
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| 13 (11) |
Calyx stellate pubescent; filament tube glabrous; mericarps 7-10. |
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5 S. rhombifolia |
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Calyx stellate tomentose; filament tube hairy; mericarps 6-8. |
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6 S. alnifolia |
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List of lower taxa
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