Lepidium draba |
Lepidium ruderale |
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heart-pod hoary-cress, heart-pod pepperweed, hoary cress, hoary pepperwort, whitetop |
narrow-leaf pepper-grass, roadside pepper-grass, roadside pepperweed, stinking pepper-weed |
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Habit | Perennials; (rhizomatous); hirsute or glabrate. | Annuals or biennials; (fetid); puberulent (trichomes cylindrical). |
Stems | often simple from base, erect or decumbent basally, branched (several) distally, (0.8–)2–6.5(–9) dm. |
simple from base, erect ascending, branched (several) distally, (0.5–)1–3.5(–5.5) dm. |
Basal leaves | (early withered); not rosulate; petiole 1–4 cm; blade obovate, spatulate, or ovate, (1.5–)3–10(–15) cm × 10–40 mm, margins sinuate to dentate or entire. |
rosulate; petiole 1–3.2(–5.3) cm; blade (1- or) 2- or 3-pinnatisect (lobes oblong), (1.5–)3–5(–7.2) cm, margins (of lobes) usually entire, rarely dentate. |
Cauline leaves | sessile; blade ovate, elliptic, oblong, or lanceolate, oblanceolate, or obovate, (1–)3–9(–15) cm × (5–)10–20(–50) mm, base sagittate-amplexicaul or auriculate, margins dentate or entire, (surfaces pubescent or glabrous). |
sessile; blade linear, (0.4–)1–2(–3) cm × 0.5–2.5(–3.5) mm, base cuneate, not auriculate, margins entire. |
Racemes | (corymbose panicles), slightly or considerably elongated in fruit; rachis glabrous or puberulent, trichomes straight or curved, cylindrical. |
considerably elongated in fruit; rachis puberulent, trichomes straight, cylindrical. |
Flowers | sepals oblong to ovate, 1.5–2.5 × 0.7–1.2 mm; petals white, obovate, (2.5–)3–4(–4.5) × (1–)1.3–2(–2.2) mm, claw 1–1.7 mm; stamens 6; filaments 2–3 mm, (glabrous); anthers 0.4–0.5 mm. |
sepals oblong, 0.5–0.9(–1) × 0.2–0.4 mm; petals (absent or rudimentary), white, linear, 0.2–0.5 × 0.1 mm, claw absent; stamens 2, median; filaments 0.7–0.8 mm; anthers 0.1–0.2 mm. |
Fruiting pedicels | ascending to horizontal, straight, (terete), 5–10(–15) × 0.2–0.3 mm, glabrous or sparsely puberulent adaxially. |
divaricate to horizontal, straight, (terete), (1.5–)2–4(–5) × 0.1–0.15 mm, puberulent. |
Fruits | (indehiscent), cordate to subreniform, (2–)2.5–3.7(–4.3) × (3.2–)3.7–5(–5.6) mm, apically (obtuse to subacute), not winged, apical notch absent; valves thin, smooth, reticulate-veined, glabrous; style (0.6–)1–1.8(–2) mm. |
elliptic, (1.5–)1.8–2.5(–3) × 1.5–2(–2.3) mm, apically winged, apical notch 0.1–0.2 mm deep; valves thin, smooth, not veined, glabrous; style obsolete or to 0.1 mm, included in apical notch. |
Seeds | ovate, 1.5–2.3 × 1–1.3 mm. |
oblong to ovate-oblong, 1–1.5 × 0.6–0.8 mm. |
2n | = 32, 64. |
= 16, 32. |
Lepidium draba |
Lepidium ruderale |
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Phenology | Flowering Apr–Aug. | Flowering Apr–Jul. |
Habitat | Mountain slopes, roadsides, fields, agricultural lands, stream sides, disturbed grounds, pastures, waste areas | Fields, pastures, waste places, roadsides, gardens |
Elevation | 0-3300 m (0-10800 ft) | 0-300 m (0-1000 ft) |
Distribution |
AZ; CA; CO; CT; DC; IA; ID; IL; IN; KS; MA; MD; MI; MN; MO; MT; ND; NE; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SD; UT; WA; WY; AB; BC; MB; NS; ON; SK; s Europe; sw Asia [Introduced in North America; introduced also in Mexico (Distrito Federal), South America, s Africa, Australia]
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AL; AR; CA; DE; FL; IN; LA; MA; MD; ME; MI; NC; NH; NJ; NM; NY; OH; OR; PA; RI; TN; TX; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK; Eurasia [Introduced in North America; introduced also in South America, Australia]
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Discussion | Although Lepidium draba is poorly established and known from old collections in the eastern part of the United States, it has become a noxious weed in several western states. Lepidium draba and its nearest relatives, L. appelianum and L. chalepense, form a monophyletic clade most closely related to L. campestre (K. Mummenhoff et al. 2001). A. Thellung (1906) and C. L. Hitchcock (1936) correctly placed L. draba in Lepidium, as did Linnaeus. The recognition of the first three species in Cardaria and the maintenance of their nearest relative, L. campestre, in Lepidium do not make any sense on both phylogenetic and taxonomic grounds. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 581. | FNA vol. 7, p. 592. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | Cardaria draba, Cochlearia draba, Nasturtium draba | L. texanum, L. virginicum subsp. texanum |
Name authority | Linnaeus: Sp. Pl. 2: 645. (1753) | Linnaeus: Sp. Pl. 2: 645. (1753) |
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