Allium cernuum |
Allium acuminatum |
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lady's leek, nodding onion |
Hooker's onion, taper-tip 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. |
1–12+, not basally clustered, not forming rhizomes, ovoid to ± globose, 0.8–1.6 × 0.9–1.6 cm; outer coats enclosing 1 or more renewal bulbs, ± yellow-brown, prominently cellular-reticulate, membranous, cells square or polygonal, walls thick, obscurely sinuous, without fibers; inner coats white, cells obscure, ± quadrate. |
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. |
persistent, withering from tip by anthesis, 2–3, basally sheathing, sheaths not extending much above soil surface; blade solid, subterete or ± channeled, 7–30 cm × 1–3 mm, margins entire. |
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. |
persistent, solitary, erect, solid, terete, 10–35 cm × 1–3 mm. |
Umbel | persistent, cernuous, loose, 8–35-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2, 3-veined, lanceolate, ± equal, apex acuminate, beakless. |
persistent, erect, loose, 10–40-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2, 3–7-veined, lanceolate to ovate, ± equal, apex acuminate. |
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, 8–15 mm; tepals erect, pink to rose-purple, or white, lanceolate to lance-ovate, unequal, becoming rigid and keeled in fruit, margins finely denticulate (inner tepal more prominently so), apex acuminate, outer tepal longer and wider than inner, spreading to recurved at tip, inner tepal with strongly recurved tips; stamens included; anthers yellow; pollen yellow; ovary crested; processes 3, central, 2-lobed, rounded, minute, margins entire; style linear, equaling stamens; stigma capitate, scarcely thickened, obscurely 3-lobed; pedicel 6–25 mm. |
Seed | coat dull or shining; cells smooth, minutely roughened, or each with minute, central papilla. |
coat dull or shining; cells minutely roughened. |
2n | = 14. |
= 14. |
Allium cernuum |
Allium acuminatum |
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Phenology | Flowering Jul–Oct. | Flowering Apr–Jul. |
Habitat | Widely distributed on moist soils in mountainous and cool regions | Dry slopes and plains |
Elevation | 600–3500 m (2000–11500 ft) | 100–1500 m (300–4900 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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AZ; CA; CO; ID; NV; OR; UT; WA; WY; BC
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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.) |
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Source | FNA vol. 26, p. 247. | FNA vol. 26, p. 261. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | A. allegheniense, A. oxyphilum, A. recurvatum | A. acuminatum var. cuspidatum, A. cuspidatum |
Name authority | Roth: Arch. Bot. (Leipzig) 1: 40. (1798) | Hooker: Fl. Bor.-Amer. 2: 184, plate 196. (1838) |
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