Lepidium draba |
Lepidium eastwoodiae |
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heart-pod hoary-cress, heart-pod pepperweed, hoary cress, hoary pepperwort, whitetop |
mesa pepperwort |
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Habit | Perennials; (rhizomatous); hirsute or glabrate. | Annuals, biennials, or perennials; (base woody); glabrous or pubescent. |
Stems | often simple from base, erect or decumbent basally, branched (several) distally, (0.8–)2–6.5(–9) dm. |
simple from base, erect, branched distally, (3.5–)4.5–16(–18) 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. |
(soon deciduous), not rosulate; petiole (1–)2–5.5(–7.5) cm; blade pinnatifid, (2–)3–6.8(–9) cm × 10–30 mm, margins (of lobes) dentate to serrate. |
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). |
shortly petiolate or sessile; blade narrowly lanceolate or oblanceolate to linear, 3–7 cm × (2.5–)4–10mm (smaller distally), base attenuate to cuneate, not auriculate, margins usually entire, rarely dentate. |
Racemes | (corymbose panicles), slightly or considerably elongated in fruit; rachis glabrous or puberulent, trichomes straight or curved, cylindrical. |
elongated in fruit; rachis puberulent, trichomes straight or curved. |
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 suborbicular to oblong, 0.8–1.5 × 0.7–1.2 mm; petals white, suborbicular, 2.2–3.5(4) × 1.5–2.5 mm, claw 0.7–1.5 mm; stamens 6; filaments 1.5–2.5 mm, (glabrous); anthers 0.3–0.4 mm. |
Fruiting pedicels | ascending to horizontal, straight, (terete), 5–10(–15) × 0.2–0.3 mm, glabrous or sparsely puberulent adaxially. |
divaricate-ascending to horizontal, usually slightly recurved or somewhat sigmoid, rarely straight, (not winged), (3–)3.5–7.5(–8) × 0.2–0.3 mm, puberulent adaxially. |
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 ovate, 2–3.5(–4) × 1.8–2.6(–3) mm, apically winged, apical notch 0.1–0.2mm deep; valves thin, smooth, not veined, glabrous; style (0.2–)0.3–0.6(–0.7) mm, exserted beyond apical notch. |
Seeds | ovate, 1.5–2.3 × 1–1.3 mm. |
(dark brown), ovate, 1.4–1.8 × 0.8–1.1 mm. |
2n | = 32, 64. |
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Lepidium draba |
Lepidium eastwoodiae |
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Phenology | Flowering Apr–Aug. | Flowering Jul–Sep. |
Habitat | Mountain slopes, roadsides, fields, agricultural lands, stream sides, disturbed grounds, pastures, waste areas | Pinyon-juniper, sagebrush, or mixed desert shrub communities |
Elevation | 0-3300 m (0-10800 ft) | 900-2200 m (3000-7200 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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AZ; CO; NM; UT
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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.) |
C. L. Hitchcock (1936) and R. C. Rollins (1993) reduced Lepidium eastwoodiae to a variety of L. montanum and L. alyssoides, respectively. However, the differences in morphology and flowering periods support its recognition as an independent species. We have not examined the holotype of Lepidium moabense and follow N. H. Holmgren (2005b) in reducing it to synonymy of L. eastwoodiae. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 581. | FNA vol. 7, p. 581. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | Cardaria draba, Cochlearia draba, Nasturtium draba | L. alyssoides var. eastwoodiae, L. moabense, L. montanum var. eastwoodiae |
Name authority | Linnaeus: Sp. Pl. 2: 645. (1753) | Wooton: Bull. Torrey Bot. Club 25: 258. (1898) |
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