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20. Chenopodium Linnaeus, Sp. Pl. 1: 218. 1753.
藜属 li shu
Herbs annual or perennial, rarely subshrubs, covered with vesicular or terete hairs (in several species sometimes also with uniseriate, multicellular hairs), farinose (“mealy”) when dry, rarely glabrous. Leaves alternate, petiolate; leaf blade complanate, margin entire or irregularly serrate or lobed. Inflorescence usually of several flowers forming a glomerule (rarely solitary flowers), these arranged in axillary or terminal spikes, panicles, or dichasia; bracts and bractlets absent. Flowers bisexual or some female. Perianth green, globose, 5-parted, in some species (2 or)3- or 4-parted; segments abaxially slightly fleshy at center or longitudinally keeled, adaxially concave, remaining unchanged in fruit, rarely enlarged or becoming juicy, without appendages. Disk usually absent. Stamens 5 or fewer; filaments sometimes basally united, filiform or capillary; anthers oblong, without an appendage. Ovary globose, slightly depressed, rarely ovoid; ovule subsessile; style obscure or very short; stigmas 2(-5). Fruit a utricle; pericarp membranous or slightly fleshy, adnate to seed or free, indehiscent. Seed horizontal, in some species oblique and/or vertical, ovoid, lenticular, or depressed globose; testa lustrous, leathery, smooth or pitted; embryo annular, semi-annular, or horseshoe-shaped; perisperm copious, farinaceous.
About 170 species: almost worldwide, but most abundant in temperate and subtropical zones; 15 species (one introduced) in China.
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| 1 |
Perianth 3- or 4-parted; seeds horizontal, vertical, or oblique. |
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(2) |
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Perianth mostly 5-parted; seeds always horizontal (sometimes oblique or vertical in C. urbicum subsp. sinicum). |
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(5) |
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| 2 (1) |
Flowers arranged in dense, axillary, globose inflorescences; perianth becoming red and succulent in fruit. |
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1 C. foliosum |
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Flowers not arranged in axillary, globose inflorescences; perianth not becoming red and succulent in fruit. |
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(3) |
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| 3 (2) |
Perianth segments mostly united to near apex. |
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4 C. chenopodioides |
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Perianth segments united only at base. |
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(4) |
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| 4 (3) |
Plants farinose; leaves grayish white abaxially. |
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2 C. glaucum |
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Plants glabrous to weakly farinose; leaves concolorous. |
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3 C. rubrum |
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| 5 (1) |
Leaf blade margin entire, or with a pair of simple or divided lateral lobes below middle. |
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(6) |
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Leaf blade margin ± toothed. |
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(10) |
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| 6 (5) |
Inflorescences shorter than leaves. |
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(7) |
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Inflorescences longer than leaves. |
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(8) |
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| 7 (6) |
Leaves 1.5-3 cm; seed finely foveolate. |
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8 C. karoi |
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Leaves 0.5-1.5 cm; seed subsmooth. |
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9 C. iljinii |
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| 8 (6) |
Inflorescence crowded, rachis or beneath flowers with fascicles of terete hairs; leaf blade margin narrowly pellucid; perianth mostly thickened in fruit and becoming star-shaped. |
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5 C. acuminatum |
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Inflorescence slender and loose, rachis without fascicles of terete hairs; leaf blade margin not pellucid; perianth not thickened in fruit. |
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(9) |
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| 9 (8) |
Leaf blade margin with distinct, lateral lobes, sometimes lobes 2-divided; perianth segments ovate; seed radially lineate. |
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6 C. bryoniifolium |
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Leaf blade margin entire or with obscure, lateral lobes; perianth segments narrowly obovate to linear; seed pitted. |
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7 C. gracilispicum |
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| 10 (5) |
Plants glabrous throughout. |
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10 C. urbicum |
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Plants ± farinose. |
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(11) |
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| 11 (10) |
Leaf blade margin palmately lobed; seed usually 2-3 mm in diam., distinctly orbicular pitted. |
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11 C. hybridum |
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Leaf blade margin not palmately lobed; seed less than 2 mm in diam., not orbicular pitted. |
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(12) |
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| 12 (11) |
Plants 2-3 m tall; lower leaves to 20 cm; inflorescence pendulous. |
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12 C. giganteum |
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Plants usually smaller; lower leaves less than 8 cm; inflorescence not pendulous. |
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(13) |
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| 13 (12) |
Leaf blade margin distinctly 3-lobed, middle and lateral lobes serrate; seed hexagonally pitted; perianth segments valvate in bud and remaining closed at anthesis. |
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13 C. ficifolium |
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Leaf blade margin not 3-lobed; seed lightly lineate; perianth segments imbricate in bud and spreading in flower. |
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(14) |
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| 14 (13) |
Leaf blade margins nearly parallel, apex rounded or obtuse. |
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14 C. strictum |
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Leaf blade margins distinctly non-parallel, apex acute or acuminate. |
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15 C. album |
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List of lower taxa
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Treatments in Other Floras @ www.efloras.org
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