Lepidium draba |
Lepidium campestre |
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heart-pod hoary-cress, heart-pod pepperweed, hoary cress, hoary pepperwort, whitetop |
field cress, field pepper-grass, field pepper-weed, field peppergrass pepperwort |
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Habit | Perennials; (rhizomatous); hirsute or glabrate. | Annuals; densely hirsute. |
Stems | often simple from base, erect or decumbent basally, branched (several) distally, (0.8–)2–6.5(–9) dm. |
simple from base, erect, unbranched or branched distally, (0.8–)1.2–5(–6.3) 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 (0.5–)1.5–6 cm; blade oblanceolate or oblong, (1–)2–6(–8) cm × 5–15 mm, margins entire, lyrate, or pinnatifid. |
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; oblong, lanceolate, or narrowly deltate-lanceolate, (0.7–)1–4(–6.5) cm × (2–)5–10(–15) mm, base sagittate or auriculate, margins dentate or subentire. |
Racemes | (corymbose panicles), slightly or considerably elongated in fruit; rachis glabrous or puberulent, trichomes straight or curved, cylindrical. |
much-elongated in fruit; rachis hirsute, trichomes spreading, straight. |
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, (1–)1.3–1.8 × 0.6–0.8 mm; petals white, spatulate, (1.5–)1.8–2.5(–3) × (0.2–)0.5–0.7 mm, claw 0.6–1 mm; stamens 6; filaments (1.2–)1.5–1.8(–2) mm, (glabrous); anthers 0.3–0.5 mm. |
Fruiting pedicels | ascending to horizontal, straight, (terete), 5–10(–15) × 0.2–0.3 mm, glabrous or sparsely puberulent adaxially. |
horizontal, straight or slightly recurved, (terete), (3–)4–8(–10) × 0.3–0.4 mm, hirsute. |
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. |
broadly oblong to ovate, (4–)5–6(–6.5) × (3–)4–5 mm, (curved adaxially), apically broadly winged, apical notch (0.2–)0.4–0.6 mm deep; valves thin, papillate except for wing, not veined; style 0.2–0.5(–0.7) mm, slightly exserted beyond, or included in, apical notch. |
Seeds | ovate, 1.5–2.3 × 1–1.3 mm. |
(dark brown), ovoid, 2–2.3(–2.8) × 1–1.4 mm. |
2n | = 32, 64. |
= 16. |
Lepidium draba |
Lepidium campestre |
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Phenology | Flowering Apr–Aug. | Flowering May–Jun. |
Habitat | Mountain slopes, roadsides, fields, agricultural lands, stream sides, disturbed grounds, pastures, waste areas | Roadside, pastures, gardens, open flats, pine woodlands, rocky slopes, forests, waste grounds, disturbed areas, meadows, fields |
Elevation | 0-3300 m (0-10800 ft) | 0-2600 m (0-8500 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; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MO; MS; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SC; TN; UT; VA; VT; WA; WI; WV; WY; BC; NF; NS; ON; PE; QC; SK; Europe; Asia [Introduced in North America; introduced also in South America, South Africa]
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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. 577. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | Cardaria draba, Cochlearia draba, Nasturtium draba | Thlaspi campestre, Neolepia campestris |
Name authority | Linnaeus: Sp. Pl. 2: 645. (1753) | (Linnaeus) W. T. Aiton: in W. Aiton and W. T. Aiton, Hortus Kew. 4: 88. (1812) |
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