Lepidium alyssoides |
Lepidium acutidens |
|
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mesa pepperwort |
alkali pepperwort, alkali veiny pepper-grass, net pepper grass |
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Habit | Perennials or subshrubs; (woody base often aboveground); glabrous or minutely puberulent. | Annuals; hirsute or puberulent. |
Stems | few to several from base, erect to ascending, branched throughout, (0.7–)1–4.8(–6.1) dm. |
few to several from base, erect to ascending, unbranched, (0.5–)0.8–3 dm. |
Basal leaves | often not rosulate; petiole 1–6 cm; blade pinnately lobed, (1–)1.5–8(–11) cm × (5–)10–35 mm, margins (of lobes) entire or denticulate. |
(soon withered); not rosulate; petiole 1–4 cm; blade linear or pinnatisect, (2–)2.5–6.1(–7.2) cm × (0.5–)1–2(–3) mm, (lobes linear to narrowly oblong), margins entire. |
Cauline leaves | sessile; blade linear, (0.8–)1.3–7(–9.5) cm × (0.7–)1–2(–3) mm, base attenuate, not auriculate, margins entire. |
sessile; blade linear, 1.2–5.8 cm × 0.5–2(–3) mm, base attenuate, not auriculate, margins entire. |
Racemes | elongated in fruit; rachis puberulent or glabrous. |
elongated, (dense or lax) in fruit; rachis puberulent or hirsute, trichomes straight, cylindrical. |
Flowers | sepals ovate to oblong, 1–2 × 0.8–1 mm; petals white, suborbicular, 2–3 × 1–2 mm, claw 0.5–1.5 mm; stamens 6; filaments 1.5–2 mm, (glabrous); anthers 0.2–0.4 mm. |
sepals oblong to ovate, 0.7–1.1 × 0.2–0.6 mm; petals absent; stamens 4, median; filaments 0.5–1 mm; anthers ca. 0.1 mm. |
Fruiting pedicels | divaricate to horizontal, straight or recurved to somewhat sigmoid, (terete), 3.5–8(–11) × 0.2 mm, glabrous or puberulent adaxially. |
erect to slightly ascending, straight and appressed to rachis or distally slightly recurved, (strongly flattened), (2–)3–4.2 × 0.4–0.6 mm (width proximal to apex), puberulent throughout. |
Fruits | broadly ovate, 2–3.7(–4.3) × (1.5–)1.8–2.9(–3.4) mm, apically winged, apical notch 0.1–0.3(–0.4) mm deep; valves thin, smooth, not veined, glabrous; style 0.2–0.6 mm, exserted beyond apical notch. |
ovate to ovate-oblong, (3–)4–6 × 2.5–3.5 mm, apically winged, apical notch (V-shaped), (0.8–)1–2 mm deep; valves thin, smooth, strongly reticulate-veined, usually glabrous, rarely pubescent; style absent or obsolete, included in apical notch. |
Seeds | ovate, 1.5–1.8(–2) × 0.9–1.2(–1.5) mm. |
ovate, 1.3–2 × 0.8–1.2 mm. |
2n | = 32. |
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Lepidium alyssoides |
Lepidium acutidens |
|
Phenology | Flowering May–Jul. | Flowering Feb–Apr. |
Habitat | Pinyon-juniper or sagebrush communities, prairies, grasslands, sandstone outcrops, gypsum flats, sand dunes, dry flats and river bottoms, gravelly roadsides | Alkaline flats, gullies, or fields, saline vernal flats, grassy fields |
Elevation | 1200-2800 m (3900-9200 ft) | 0-400 m (0-1300 ft) |
Distribution |
AZ; CO; NM; NV; TX; UT; WY; Mexico (Chihuahua, Coahuila, Nuevo León, San Luis Potosí)
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CA; OR; Mexico (Baja California)
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Discussion | Of the five varieties of Lepidium alyssoides recognized by R. C. Rollins (1993), one (var. mexicanum Rollins) is a short-tufted form of the species restricted to Mexico that does not seem to merit recognition, another (var. junceum) is a glabrescent form of the type variety, a third (var. eastwoodiae) is treated below as a distinct species, and the fourth (var. angustifolium) is included here within L. alyssoides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Lepidium acutidens was treated by C. L. Hitchcock (1936) and R. C. Rollins (1993) as a variety of L. dictyotum. The differences in the fruits as well as the absence of intermediates between them, despite the overlap of their ranges in California, justify their recognition as independent species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 575. | FNA vol. 7, p. 575. |
Parent taxa | Brassicaceae > tribe Lepidieae > Lepidium | Brassicaceae > tribe Lepidieae > Lepidium |
Sibling taxa | ||
Synonyms | L. alyssoides var. angustifolium, L. alyssoides var. junceum, L. alyssoides var. minus, L. alyssoides var. polycarpum, L. alyssoides var. streptocarpum, L. montanum subsp. alyssoides, L. montanum var. alyssoides, L. montanum subsp. angustifolium, L. montanum var. angustifolium, L. tortum | L. dictyotum var. acutidens, L. oxycarpum var. acutidens |
Name authority | A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 10. (1849) | (A. Gray) Howell: Fl. N.W. Amer., 64. (1897) |
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