Lepidium eastwoodiae |
Lepidium draba |
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mesa pepperwort |
heart-pod hoary-cress, heart-pod pepperweed, hoary cress, hoary pepperwort, whitetop |
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Habit | Annuals, biennials, or perennials; (base woody); glabrous or pubescent. | Perennials; (rhizomatous); hirsute or glabrate. |
Stems | simple from base, erect, branched distally, (3.5–)4.5–16(–18) dm. |
often simple from base, erect or decumbent basally, branched (several) distally, (0.8–)2–6.5(–9) dm. |
Basal leaves | (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. |
(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. |
Cauline leaves | 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. |
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). |
Racemes | elongated in fruit; rachis puberulent, trichomes straight or curved. |
(corymbose panicles), slightly or considerably elongated in fruit; rachis glabrous or puberulent, trichomes straight or curved, cylindrical. |
Flowers | 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. |
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. |
Fruiting pedicels | 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. |
ascending to horizontal, straight, (terete), 5–10(–15) × 0.2–0.3 mm, glabrous or sparsely puberulent adaxially. |
Fruits | 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. |
(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. |
Seeds | (dark brown), ovate, 1.4–1.8 × 0.8–1.1 mm. |
ovate, 1.5–2.3 × 1–1.3 mm. |
2n | = 32, 64. |
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Lepidium eastwoodiae |
Lepidium draba |
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Phenology | Flowering Jul–Sep. | Flowering Apr–Aug. |
Habitat | Pinyon-juniper, sagebrush, or mixed desert shrub communities | Mountain slopes, roadsides, fields, agricultural lands, stream sides, disturbed grounds, pastures, waste areas |
Elevation | 900-2200 m (3000-7200 ft) | 0-3300 m (0-10800 ft) |
Distribution |
AZ; CO; NM; UT
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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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Discussion | 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.) |
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.) |
Source | FNA vol. 7, p. 581. | FNA vol. 7, p. 581. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | L. alyssoides var. eastwoodiae, L. moabense, L. montanum var. eastwoodiae | Cardaria draba, Cochlearia draba, Nasturtium draba |
Name authority | Wooton: Bull. Torrey Bot. Club 25: 258. (1898) | Linnaeus: Sp. Pl. 2: 645. (1753) |
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