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42. Petrosimonia Bunge, Mém. Acad. Imp. Sci. Saint Pétersbourg, sér. 7. 4(11): 19, 52. 1862.
叉毛蓬属 cha mao peng shu
Herbs annual, ephemeral, appressed sericeous-villous, rarely glabrous. Stem much branched, terete. Leaves sessile, linear, terete or semiterete, apex acute or acuminate. Flowers axillary, solitary, bisexual, with 2 navicular, embracing bractlets. Perianth segments 2, 3, or 5, narrowly ovate-lanceolate to elliptic, slightly enlarged in fruit, membranous or papery, proximally becoming leathery and adaxially concave, without an appendage, veinless, glabrous or abaxially slightly hairy near apex. Stamens 1-5, inserted on an obscure disk; filaments compressed; anthers oblong or sagittate, exserted from perianth; connective protruding, becoming a thickened, solid appendage. Ovary broadly ovoid, compressed; ovule subsessile; style cylindric; stigmas 2, filiform. Utricle enclosed in perianth, ovate or broadly oblong; pericarp membranous or thinly papery, slightly fleshy distally, glabrous, not adnate to seed. Seed vertical, globose or subglobose, compressed; testa membranous; embryo planospiral; perisperm absent.
Between 11 and 15 species; C and SW Asia, SE Europe; four species in China.
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| 1 |
Branches and leaves all opposite; perianth segments 5. |
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1 P. sibirica |
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Branches and leaves opposite below, alternate above; perianth segments 2 or 3. |
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(2) |
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| 2 (1) |
Branches and leaves opposite, except apical ones (in inflorescence) alternate; plants densely pubescent with long, semiappressed hairs. |
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2 P. squarrosa |
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Branches and leaves opposite only on lower stem, all others alternate; plants pubescent with short, appressed hairs or subglabrous. |
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(3) |
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| 3 (2) |
Plants blue-gray; lower branches suberect; bracts recurved or reflexed at apex, all longer than subtended flower. |
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3 P. glaucescens |
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Plants reddish or yellowish green; lower branches prostrate; bracts erect, upper ones shorter than subtended flower. |
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4 P. oppositifolia |
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Lower Taxa
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