Allium cernuum |
Allium obtusum |
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lady's leek, nodding onion |
red Sierra onion, red Sierran onion |
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Bulbs | 2–5+, clustered, often short-rhizomatous at base, rhizome not stout or iris-like, oblong, elongate, 1–3 × 0.8–1.5 cm; outer coats enclosing 1 or more bulbs, grayish or brownish, membranous, minutely striate, cells in regular vertical rows, narrowly elongate, fibers persistent, parallel, few; inner coats white to pink or reddish, cells in regular vertical rows, narrowly elongate. |
1–5, not clustered on stout primary rhizome, ovoid, 1–2 × 0.8–1.8 cm; outer coats enclosing 1 or more bulbs, brown, membranous, cellular-reticulate, cells quadrate, polygonal, or ± rectangular, ± transversely elongate, without fibers; inner coats white, reticulation absent or cells obscure, ± quadrate. |
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Leaves | persistent, green at anthesis, 3–5, basally sheathing, sheaths not extending much above soil level; blade solid, flat, channeled to broadly V-shaped in cross section, 10–25 cm × 1–6 mm, margins entire or denticulate. |
usually deciduous with scape, withering from tip at anthesis, 1–2, basally sheathing, sheaths not extending much above soil surface; blade solid, flat or broadly channeled, ± falcate, 5–22 cm × 0.5–14 mm, margins entire. |
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Scape | persistent, sometimes 2 or more produced successively from single bulb, usually clustered, nodding, solid, terete or ridged, particularly distally, sometimes flattened and narrowly winged, abruptly recurved near apex, 10–50 cm × 1–3 mm. |
usually forming abcission layer and deciduous with leaves after seeds mature, frequently breaking at this level after pressing, solitary, erect, solid, terete, 2–17 cm × 0.5–2 mm. |
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Umbel | persistent, cernuous, loose, 8–35-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2, 3-veined, lanceolate, ± equal, apex acuminate, beakless. |
persistent, erect, compact, 6–65-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2–3(–5), 5-8-veined, ovate, ± equal, apex abruptly acuminate to apiculate. |
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Flowers | campanulate, 4–6 mm; tepals ± erect, pink or white, elliptic-ovate, ± equal, withering in fruit, margins ± entire, apex ± obtuse, at least outer tepals strongly incurved, midribs not thickened; stamens exserted; anthers yellow; pollen yellow; ovary conspicuously crested; processes 6, flattened, ± triangular, margins entire or toothed; style exserted, linear, ± equaling stamens; stigma capitate, scarcely thickened, unlobed; pedicel 6–25 mm, becoming stouter in fruit, elongating and bending abruptly upward from near point of attachment. |
campanulate, 4–12 mm; tepals erect, white or pink with dark purplish midveins, lanceolate to oblong-elliptic, ± equal, becoming papery in fruit, margins entire, apex obtuse to acute; stamens included; anthers yellow or purple; pollen yellow; ovary crested; processes 3, obscure to ± prominent, rounded, central, margins entire; style linear, equaling stamens or longer; stigma capitate, scarcely thickened, obscurely 3-lobed; pedicel 2–14(–20) mm. |
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Seed | coat dull or shining; cells smooth, minutely roughened, or each with minute, central papilla. |
coat dull; cells ± smooth. |
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2n | = 14. |
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Allium cernuum |
Allium obtusum |
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Phenology | Flowering Jul–Oct. | |||||
Habitat | Widely distributed on moist soils in mountainous and cool regions | |||||
Elevation | 600–3500 m (2000–11500 ft) | |||||
Distribution |
AL; AR; AZ; CO; DC; GA; IA; ID; IL; IN; KY; MD; MI; MN; MO; MT; NC; NE; NM; NY; OH; OR; PA; SC; SD; TN; TX; UT; VA; WA; WI; WV; WY; AB; BC; ON; SK; Mexico
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CA; NV
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Discussion | Allium cernuum is the most widespread North American species of the genus. It is closely related to A. stellatum, and the character commonly used to differentiate them has been umbel orientation. In both species, the inflorescence is nodding in bud, but in A. stellatum it usually becomes erect by anthesis. In A. cernuum the peduncle remains permanently recurved near the apex, although the inflorescence may sometimes become erect overall, or nearly so. While this character is helpful in identification, an almost exclusive reliance on it (even by one of the present authors in his youth) has obscured other clearer distinctions between the species and has confused their geographic ranges. More reliable characters for differentiating these species are bulb shape (elongate in A. cernuum, ovoid in A. stellatum) and perianth shape (campanulate in A. cernuum, stellate in A. stellatum). Unfortunately, perianth shape is often difficult to see in herbarium specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). Allium obtusum is known only from the Sierra Nevada. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 26, p. 247. | FNA vol. 26, p. 269. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | A. allegheniense, A. oxyphilum, A. recurvatum | |||||
Name authority | Roth: Arch. Bot. (Leipzig) 1: 40. (1798) | Lemmon: Pittonia 2: 69. (1890) | ||||
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