Allium anceps |
Allium cepa |
|
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Kellogg's onion, twin leaf onion, two-edge onion |
cultivated onion, garden onion |
|
Bulbs | 1–5, not clustered on stout primary rhizome, ovoid, 1.5–2 × 1.2–2 cm; outer coats enclosing 1 or more bulbs, brown to yellow-brown, membranous, ± prominently cellular-reticulate, cells in regular vertical rows, narrowly rectangular, transversely elongate, without fibers; inner coats white, cells obscure, transversely elongate. |
1–3, not rhizomatous, mostly depressed-globose, varying in size from cultivar to cultivar, 5–8 × 3–10 cm; outer coats enclosing 1 or more bulbs, yellowish brown, red, or white, membranous, without reticulation; inner coats white to pink, cells obscure to quadrate. |
Leaves | usually deciduous with scape, withering from tip at anthesis, 2, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, falcate, 7–26 cm × 4–6 mm, margins entire. |
persistent, 4–10, sheathing proximal 1/6–1/4 scape; blade fistulose, usually ± semicircular in cross section, 10–50 cm × 4–20 mm. |
Scape | usually forming abcission layer and deciduous with leaves after seeds mature, frequently breaking at this level after pressing, solitary, erect, solid, flattened, narrowly winged, 10–15 cm × 1–3 mm. |
persistent, solitary, erect, fistulose, inflated below middle, 30–100 cm × 3–20 mm. |
Umbel | persistent, erect, ± compact, 15–35-flowered, hemispheric, bulbils unknown; spathe bracts persistent, 2, 10–13-veined, ovate, ± equal, apex acute. |
persistent, erect, compact, to 500-flowered, globose, bulbils occasionally found; spathe bracts caducous, 2–3, 3–4-veined, ovate, ± equal, apex acute to acuminate. |
Flowers | stellate, 8–12 mm; tepals spreading, light pink with diffuse greenish midveins, linear-lanceolate, ± equal, papery, withering in fruit, margins entire, apex acute; stamens ± equaling tepals; anthers yellow; pollen yellow; ovary crested; processes 6, central, rounded, minute, margins entire; style linear, 0.5 times stamens; stigma capitate, scarcely thickened, unlobed; pedicel 15–30 mm. |
stellate to campanulate to urceolate, 3–7 mm; tepals erect to ± spreading, white to pink with greenish midveins, withering in fruit, margins entire, apex obtuse or acute, outer ovate, inner oblong; stamens exserted; anthers white; pollen white; ovary crestless; style linear, ± equaling stamens; stigma capitate, unlobed; pedicel 10–50 mm. |
Seed | coats dull; cells smooth. |
coat not known. |
2n | = 14. |
|
Allium anceps |
Allium cepa |
|
Phenology | Flowering Apr–May. | Flowering Jun–Aug. |
Habitat | Heavy, generally barren, clay soils | Disturbed sites adjacent to areas where cultivated |
Elevation | 1200–1600 m (3900–5200 ft) | 0–500 m (0–1600 ft) |
Distribution |
CA; ID; NV; OR
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AR; CA; KS; LA; MT; OR; TX; WA; cultivated in Europe; Asia
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Discussion | The onion of commerce, Allium cepa is widely cultivated as a biennial in North America, Europe, and Asia. It is unknown in the wild and is probably derived from A. oschanini of central Asia. The cultivated form is often polyploid (2n = 16, 32, 54) and possibly of hybrid origin. It exists in numerous cultivars, a few of which form large bulbils in the umbel. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 26, p. 270. | FNA vol. 26, p. 244. |
Parent taxa | Liliaceae > Allium | Liliaceae > Allium |
Sibling taxa | ||
Name authority | Kellogg: Proc. Calif. Acad. Sci. 2: 109. (1863) | Linnaeus: Sp. Pl. 1: 301. (1753) |
Web links |