Allium triquetrum |
Allium cernuum |
|
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three-corner leek, three-cornered leek, white flower onion |
lady's leek, nodding onion |
|
Bulbs | 5–20+, not clustered on stout primary rhizome, rhizomes absent, increase bulbs absent or ± equaling parent bulbs, never appearing as basal cluster, ovoid, 1–2 × 1–2 cm; outer coats enclosing renewal bulbs, ± translucent, yellow-brown, obscurely cellular-reticulate, thin, membranous, meshes delicate, cells vertically elongate, contorted, without fibers; inner coats white, cells obscure, quadrate, or not visible. |
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. |
Leaves | persistent, green at anthesis, 2–3, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, not falcate, ± carinate, 15–50 cm × 3–15 mm, margins entire. |
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. |
Scape | persistent, clustered, 1–4, erect, solid, sharply 3-angled, 10–40 cm × 1–10 mm. |
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. |
Umbel | persistent, lax, loose, 3–15-flowered, ± 1-sided, bulbils unknown; spathe bracts persistent, 1–2, 3-veined, narrowly lanceolate, ± equal, apex acute. |
persistent, cernuous, loose, 8–35-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2, 3-veined, lanceolate, ± equal, apex acuminate, beakless. |
Flowers | becoming pendent, campanulate, 10–18 mm; tepals erect to spreading, white with prominent green midrib, lanceolate, ± equal, becoming membranous in fruit, margins entire, apex acute; stamens included; anthers yellow; pollen yellow; ovary crestless; style linear, ± equaling stamens; stigma capitate, scarcely thickened, unlobed; pedicel 15–25 mm. |
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. |
Seed(s) | coat dull; cells minutely roughened. |
coat dull or shining; cells smooth, minutely roughened, or each with minute, central papilla. |
2n | = 18. |
= 14. |
Allium triquetrum |
Allium cernuum |
|
Phenology | Flowering Mar–Apr. | Flowering Jul–Oct. |
Habitat | Disturbed sites | Widely distributed on moist soils in mountainous and cool regions |
Elevation | 0–100 m (0–300 ft) | 600–3500 m (2000–11500 ft) |
Distribution |
CA; sw Europe [Introduced in North America]
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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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Discussion | Allium triquetrum is a garden escape, introduced from southwestern Europe, and is potentially a noxious weed. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 26, p. 257. | FNA vol. 26, p. 247. |
Parent taxa | Liliaceae > Allium | Liliaceae > Allium |
Sibling taxa | ||
Synonyms | A. allegheniense, A. oxyphilum, A. recurvatum | |
Name authority | Linnaeus: Sp. Pl. 1: 300. (1753) | Roth: Arch. Bot. (Leipzig) 1: 40. (1798) |
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