Lepidium didymum |
Lepidium heterophyllum |
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lesser pepper-grass, lesser swine-cress, lesser wart-cress |
purple-anther field pepper-weed, purple-anther pepperweed, Smith's pepper-grass, Smith's pepperweed, Smith's pepperwort, variable leaf pepperwort, variable-leaf pepperweed |
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Habit | Annuals; (fetid); glabrous or pilose. | Perennials; (caudex branched); hirsute. |
Stems | few to several from base, erect to ascending or decumbent, branched distally, 1–4.5(–7) dm. |
branched from base, erect to ascending, often decumbent basally, unbranched or branched (few) distally, 1–5 dm. |
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). |
rosulate; petiole 1–6.2 cm; blade oblanceolate or oblong-elliptic, 1–4.5 cm × 4–14 mm, margins entire, repand, or denticulate. |
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. |
sessile; blade oblong to deltate-lanceolate, 1–3.5 cm × 3–8 mm, base sagittate or auriculate, margins dentate to denticulate. |
Racemes | elongated in fruit; rachis glabrous or pubescent, trichomes straight, cylindrical. |
much-elongated in fruit; rachis hirsute, trichomes spreading, straight. |
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. |
sepals oblong, 1.6–2.2 × 0.6–1.1 mm; petals white, spatulate, 1.8–2.8 × 0.8–1.4 mm, claw 1–2 mm; stamens 6; filaments 1.8–2.6 mm, (glabrous); anthers 0.4–0.5 mm. |
Fruiting pedicels | divaricate to horizontal, straight slightly recurved, (terete), 1.4–2.5(–4) × 0.15–2 mm, glabrous or sparsely pubescent adaxially. |
horizontal, straight or slightly recurved, (terete), 2.8–5 × 0.3–0.4 mm, hirsute. |
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. |
broadly oblong to ovate, 4–5.5 × 3.5–4 mm, (curved adaxially), apically broadly winged, apical notch 0.2–0.3 mm deep; valves thin, often not papillate, not veined; style (0.6–)1–1.5 mm, well-exserted beyond apical notch. |
Seeds | ovate, 1–1.2 × 0.7–0.8 mm. |
(dark brown), ovoid, 1.8–2.2 × 1–1.2 mm. |
2n | = 32. |
= 48. |
Lepidium didymum |
Lepidium heterophyllum |
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Phenology | Flowering Mar–Jul. | Flowering May–Jun. |
Habitat | Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas | Gravel mounds, roadsides, abandoned fields, waste grounds, disturbed sites, gardens, hillsides |
Elevation | 0-1000 m (0-3300 ft) | 0-300 m (0-1000 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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CA; CO; MA; ME; NY; OR; PA; WA; BC; NF; Europe [Introduced in North America]
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Discussion | The records from Maine and Massachusetts are based on old collections, and it is not known if Lepidium heterophyllum has become established as part of the weedy flora of those states. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 580. | FNA vol. 7, p. 582. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling 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) | Bentham: Cat. Pl. Pyrénées, 95. (1826) |
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