Lepidium didymum |
Brassicaceae tribe Lepidieae |
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lesser pepper-grass, lesser swine-cress, lesser wart-cress |
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Habit | Annuals; (fetid); glabrous or pilose. | Annuals, biennials, or perennials [lianas, shrubs]; eglandular. |
Stems | few to several from base, erect to ascending or decumbent, branched distally, 1–4.5(–7) dm. |
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Basal leaves | (soon withered); not rosulate; petiole 0.5–4(–6) cm; blade 1- or 2-pinnatisect, 1–6(–8) cm, margins (of lobes) entire or dentate (sometimes deeply lobed). |
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Cauline leaves | shortly petiolate to subsessile; blade similar to basal, smaller and less divided distally, lobes lanceolate to oblong or elliptic, 1.5–3.5(–4.5) cm ×5–12 mm, base not auriculate, margins (of lobes) entire, serrate, or incised. |
petiolate or sessile; blade base auriculate or not, margins usually entire, dentate, or pinnately divided. |
Trichomes | simple or absent. |
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Racemes | elongated in fruit; rachis glabrous or pubescent, trichomes straight, cylindrical. |
ebracteate, elongated or not in fruit. |
Flowers | sepals (tardily deciduous), ovate, 0.5–0.7(–0.9) mm; petals white, elliptic to linear, 0.4–0.5 × ca. 0.1 mm, claw absent; stamens 2, median; filaments 0.3–0.6 mm; anthers 0.1–0.2 mm. |
actinomorphic; sepals ascending to spreading, lateral pair not saccate basally; petals white, yellow, pink, or purple [orange], claw usually present, sometimes absent, distinct; filaments unappendaged, not winged; pollen 3-colpate. |
Fruiting pedicels | divaricate to horizontal, straight slightly recurved, (terete), 1.4–2.5(–4) × 0.15–2 mm, glabrous or sparsely pubescent adaxially. |
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Fruits | schizocarpic, didymous, 1.3–1.7 × 2–2.5 mm, apically not winged, apical notch 0.2–0.4 mm deep; valves thick, rugose, strongly veined, glabrous; style absent or obsolete, included in apical notch. |
silicles, usually dehiscent, unsegmented, usually angustiseptate, rarely terete; ovules 2(–4) per ovary; style distinct, obsolete, or absent; stigma entire or, rarely, 2-lobed. |
Seeds | ovate, 1–1.2 × 0.7–0.8 mm. |
aseriate; cotyledons accumbent or incumbent. |
2n | = 32. |
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Lepidium didymum |
Brassicaceae tribe Lepidieae |
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Phenology | Flowering Mar–Jul. | |
Habitat | Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas | |
Elevation | 0-1000 m (0-3300 ft) | |
Distribution |
AL; AR; AZ; CA; CT; FL; GA; LA; MA; MD; ME; MO; MS; NC; NJ; NY; OH; OR; PA; SC; TN; TX; VA; WI; WV; BC; NB; NF; NS; QC; South America [Introduced in North America; introduced also in Mexico (Sinaloa), Central America (Honduras), Europe, Asia, s Africa, Australia]
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Nearly worldwide |
Discussion | Genera 4, species ca. 235 (1 genus, 42 species in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 580. | FNA vol. 7, p. 569. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Carara didyma, Coronopus didymus, Senebiera didyma, Senebiera incisa, Senebiera pinnatifida | |
Name authority | Linnaeus: Syst. Nat. ed. 12, 2: 433. (1767): Mant Pl. 1: 92. (1767) | de Candolle: Mém. Mus. Hist. Nat. 7: 240. (1821) |
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