Lepidium didymum |
Lepidium papilliferum |
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lesser pepper-grass, lesser swine-cress, lesser wart-cress |
Idaho pepperweed |
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Habit | Annuals; (fetid); glabrous or pilose. | Annuals or biennials; puberulent, (trichomes clavate). |
Stems | few to several from base, erect to ascending or decumbent, branched distally, 1–4.5(–7) dm. |
several from base, ascending, branched (several) distally, (0.3–)0.5–2.3(–4) 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 deciduous), not rosulate; blade often bipinnately divided. |
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. |
attenuate to petiolelike base, to 1 cm; blade pinnatifid to pinnatisect, obovate to oblanceolate in outline (lobes oblong to linear), 0.5–4 cm × 3–15 mm (smaller distally), base not auriculate, margins (of lobes) entire or dentate. |
Racemes | elongated in fruit; rachis glabrous or pubescent, trichomes straight, cylindrical. |
slightly elongated, (dense) in fruit; rachis puberulent, trichomes straight or curved, clavate. |
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 ovate to broadly oblong, 1.5–2.2 × 0.8–1.1 mm; petals white, orbicular to spatulate, 2.5–3.7(–4) × 1.5–2.5 mm, claw 0.8–1.5 mm; stamens 6; filaments 1.5–2 mm, (trichomes clavate); anthers 0.4–0.6 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, straight or recurved, (not winged), (2.5–)3–6(–7.5) × 0.2–0.3 mm, puberulent adaxially or throughout. |
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. |
orbicular to broadly ovate, 2.2–3.6 × 2–3.4 mm, apically winged, apical notch 0.1–0.3 mm deep; valves thin, smooth, often not veined, glabrous; style 0.2–0.8 mm, exserted beyond apical notch. |
Seeds | ovate, 1–1.2 × 0.7–0.8 mm. |
ovate, 1.2–1.8 × 0.9–1.1 mm. |
2n | = 32. |
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Lepidium didymum |
Lepidium papilliferum |
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Phenology | Flowering Mar–Jul. | Flowering May–Jun. |
Habitat | Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas | Sagebrush plains, desert flats, edge of playa |
Elevation | 0-1000 m (0-3300 ft) | 600-1700 m (2000-5600 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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ID |
Discussion | Of conservation concern. Lepidium papilliferum is distributed in Ada, Canyon, Elmore, Gem, Owyhee, and Payette counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 580. | FNA vol. 7, p. 590. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | Carara didyma, Coronopus didymus, Senebiera didyma, Senebiera incisa, Senebiera pinnatifida | L. montanum var. papilliferum, L. montanum subsp. papilliferum |
Name authority | Linnaeus: Syst. Nat. ed. 12, 2: 433. (1767): Mant Pl. 1: 92. (1767) | (L. F. Henderson) A. Nelson & J. F. Macbride: Bot. Gaz. 56: 474. (1913) |
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