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63. Dontostemon Andrzejowski ex C. A. Meyer in Ledebour, Fl. Altaic. 3: 118. 1831.
[nom. cons.]
花旗杆属 hua qi gan shu
Alaida Dvorák; Andreoskia de Candolle; Dimorphostemon Kitagawa; Hesperidopsis (de Candolle) Kuntze.
Herbs annual, biennial, or perennial. Trichomes unicellular, eglandular, simple, straight or crisped, sometimes mixed with multicellular, multiseriate glandular ones. Stems erect or ascending, simple or branched. Basal leaves petiolate, rosulate or not, simple, entire, dentate, pinnatifid, or pectinate-pinnatifid. Cauline leaves petiolate or sessile, similar to basal. Racemes ebracteate, elongated in fruit. Fruiting pedicels ascending or divaricate. Sepals ovate, not saccate. Petals white, pink, or purple; blade broadly obovate, obcordate, spatulate, or oblanceolate, apex obtuse or emarginate; claw subequaling sepals or longer. Stamens 6, tetradynamous; median filament pairs united, sometimes free and toothed below anther or expanded to base, dilated at base; anthers ovate or oblong, often apiculate at apex. Nectar glands 4, lateral, 1 on each side of lateral stamen; median glands absent. Ovules 7-60 per ovary. Fruit dehiscent siliques, linear, terete or latiseptate; valves with a prominent midvein and often distinct marginal veins, glabrous or glandular, torulose; gynophore obsolete, rarely to 1 mm; replum flattened; septum complete; style obsolete or to 3 mm; stigma capitate, slightly lobed, rarely prominently lobed and subdecurrent. Seeds uniseriate, winged, margined, or wingless, oblong or ovate, plump or slightly flattened; seed coat reticulate, not mucilaginous when wetted; cotyledons accumbent or incumbent.
Eleven species: China, India, Japan, Kashmir, Kazakhstan, Korea, Mongolia, Nepal, Russia, Sikkim, Tajikistan; 11 species (one endemic) in China.
Dontostemon is separated from Dimorphostemon only by having united (vs. free) median staminal filaments. However, the union of filaments evolved independently within several other genera in the Brassicaceae, and the separation of these two genera is artificial.
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| 1 |
Leaves pectinate-pinnatifid, with up to 11 lobes on each side of midvein; stigma prominently 2-lobed, lobes subdecurrent |
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11 D. tibeticus |
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Leaves entire, dentate, or serrate, if pinnatifid then with multicellular glands; stigmas slightly 2-lobed, lobes not decurrent. |
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(2) |
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| 2 (1) |
Plants sparsely to densely glandular. |
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(3) |
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Plants not glandular. |
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(6) |
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| 3 (2) |
Petals (10-)12-18 × (4-)6-8 mm; fruit flattened; anthers apex obtuse, 1.5-2 mm |
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1 D. hispidus |
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Petals 2-8 × 0.5-3(-5) mm; fruit terete; anthers apiculate, 0.2-0.8 mm. |
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(4) |
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| 4 (3) |
All leaves entire; median filaments united; stems with minute twisted trichomes |
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3 D. integrifolius |
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At least basal leaves dentate, serrate, or pinnatifid; median filaments free; stems glabrous or with straight trichomes. |
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(5) |
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| 5 (4) |
Petals obovate, (5-)6-8 mm; median filaments abruptly expanded and toothed below anther; seeds apically margined; anthers 0.6-0.8 mm |
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9 D. pinnatifidus |
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Petals spatulate, 2-4(-4.5) mm; median filaments gradually expanded to base, toothless; seeds not margined; anthers 0.2-0.4 mm |
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10 D. glandulosus |
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| 6 (2) |
At least some cauline leaves petiolate, dentate |
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2 D. dentatus |
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Cauline leaves sessile, entire. |
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(7) |
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| 7 (6) |
Plants annual or biennial, never woody basally; stems with minute twisted trichomes. |
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(8) |
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Plants perennial with woody base; stems glabrous or with straight trichomes. |
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(9) |
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| 8 (7) |
Petals broadly obovate, 5-7(-8) × 2-3 mm, apex subemarginate; anthers oblong, 0.7-0.8 mm; ovules 15-25 per locule |
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3 D. integrifolius |
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Petals narrowly oblanceolate, 3-5 × 0.6-1 mm, apex obtuse; anthers ovate, 0.4-0.5 mm; ovules 30-50 per locule |
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4 D. micranthus |
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| 9 (7) |
Stems glabrous; leaves somewhat fleshy, subleathery; fruit strongly arcuate or twisted. |
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(10) |
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Stems sparsely to densely pilose; leaves not fleshy, herbaceous; fruit straight or rarely slightly curved. |
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(11) |
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| 10 (9) |
Fruit terete, strongly arcuate, 1.5-2.5 cm × 1-1.7 mm; style 1.5-2.5 mm; plants 5-10 cm tall; sepals 3-4 mm; median filaments 3.5-4 mm |
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7 D. crassifolius |
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Fruit compressed, strongly twisted, 3-5 cm × 2-2.5 mm; style rarely to 0.5 mm; plants 15-50 cm tall; sepals 5-6 mm; median filaments 6-8 mm |
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8 D. elegans |
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| 11 (9) |
Plants pilose with subappressed trichomes rarely to 1 mm; fruit 1-2.5 cm × 0.9-1.1 mm; seeds to 1.4 mm, not margined; cotyledons incumbent |
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5 D. perennis |
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Plants hirsute with spreading trichomes to 3 mm; fruit (2.5-)3-5 cm × 1.4-2 mm; seeds to 2.5 mm, margined or winged; cotyledons accumbent |
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6 D. senilis |
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List of lower taxa
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