Lepidium didymum |
Lepidium oxycarpum |
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lesser pepper-grass, lesser swine-cress, lesser wart-cress |
fork pepper-grass, fork pepperweed, fork pepperwort, sharp pod pepper grass, sharp-fruit pepperweed, sharpfruit pepperwort |
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Habit | Annuals; (fetid); glabrous or pilose. | Annuals; glabrous or puberulent. |
Stems | few to several from base, erect to ascending or decumbent, branched distally, 1–4.5(–7) dm. |
several from base, usually erect to ascending, rarely decumbent, branched, 0.4–1.5(–2) 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). |
(soon withered); not rosulate; petiole 0.5–1.5(–2) cm; blade margins entire or pinnatifid (lobes 2–5 pairs, linear to filiform), 1.5–5 cm × 0.5–2 mm. |
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; blade linear, 0.1–0.3 cm × 0.5–2 mm, base attenuate, not auriculate, margins entire. |
Racemes | elongated in fruit; rachis glabrous or pubescent, trichomes straight, cylindrical. |
considerably elongated, (lax) in fruit; rachis glabrous or puberulent, trichomes straight, cylindrical. |
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, 0.6–0.8 × 0.4–0.5 mm; petals absent; stamens 4, median; filaments 0.6–0.7; anthers ca. 0.1 mm. |
Fruiting pedicels | divaricate to horizontal, straight slightly recurved, (terete), 1.4–2.5(–4) × 0.15–2 mm, glabrous or sparsely pubescent adaxially. |
divaricate to horizontal or descending, usually recurved, rarely straight, (terete or slightly flattened), 2–4(–6) × 0.2–0.3 mm, glabrous or puberulent adaxially. |
Fruit(s) | 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. |
ovate, 2.4–3.6 × 1.8–2.5 mm, apically winged, apical notch (V-shaped), 0.3–0.8 mm deep; valves thin, smooth, strongly reticulate-veined, glabrous; style obsolete or to 0.1 mm, included in apical notch. |
Seeds | ovate, 1–1.2 × 0.7–0.8 mm. |
oblong, 1.4–1.8 × 0.8–0.9 mm. |
2n | = 32. |
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Lepidium didymum |
Lepidium oxycarpum |
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Phenology | Flowering Mar–Jul. | Flowering Mar–May. |
Habitat | Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas | Borders of vernal pools, grassy fields, roadsides ditches, alkaline flats, margins of salt marshes |
Elevation | 0-1000 m (0-3300 ft) | 0-400 m (0-1300 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
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Discussion | Lepidium oxycarpum apparently did not persist in British Columbia following its introduction there over 110 years ago (G. A. Mulligan 2002b). That record is based on Macoun s.n. (GH, MO, NY, US), which was collected on 31 May 1893 from the vicinity of Victoria, Vancouver Island. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 580. | FNA vol. 7, p. 589. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | Carara didyma, Coronopus didymus, Senebiera didyma, Senebiera incisa, Senebiera pinnatifida | Nasturtium oxycarpum |
Name authority | Linnaeus: Syst. Nat. ed. 12, 2: 433. (1767): Mant Pl. 1: 92. (1767) | Torrey & A. Gray: Fl. N. Amer. 1: 116. (1838) |
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