Allium columbianum |
Allium cepa |
|
---|---|---|
Columbia onion, Columbian onion |
cultivated onion, garden onion |
|
Bulbs | 1–5+, not clustered on stout, primary rhizome, ovoid, 1–1.5 × 0.8–1.4 cm; outer bulb coats brownish or grayish, enclosing 1 or more bulbs, membranous, lacking cellular reticulation or cells arranged in only 2–3 rows distal to roots, ± quadrate, without fibers; inner coats white to pink, cells obscure, ± quadrate. |
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 persistent, green at anthesis, 2, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, broadly channeled, ± falcate, 10–35 cm × (2–)5–8 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 | persistent, solitary, erect, solid, terete, enlarged proximal to inflorescence, (10–)20–30(–40) cm × 1.5–4 mm. |
persistent, solitary, erect, fistulose, inflated below middle, 30–100 cm × 3–20 mm. |
Umbel | persistent, erect, compact, 25–50-flowered, hemispheric to globose, bulbils unknown; spathe bracts persistent, 3, 5–7-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, (6–)7–8(–10) mm; tepals spreading, light pink to purple with prominent green midribs, narrowly lanceolate, ± equal, becoming papery in fruit, margins entire, apex acuminate; stamens equaling or longer than tepals; anthers blue-gray; pollen light blue to gray; ovary crested; processes 6, 2 per lobe, low, rounded, margins entire; style exserted, linear; stigma capitate, scarcely thickened, unlobed; pedicel 10–20 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 | coat shining; cells smooth. |
coat not known. |
2n | = 14. |
|
Allium columbianum |
Allium cepa |
|
Phenology | Flowering May–Jul. | Flowering Jun–Aug. |
Habitat | Winter-wet, shallow soils on rock outcrops, or wet meadows | Disturbed sites adjacent to areas where cultivated |
Elevation | 300–1100 m (1000–3600 ft) | 0–500 m (0–1600 ft) |
Distribution |
ID; MT; WA
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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. | FNA vol. 26, p. 244. |
Parent taxa | Liliaceae > Allium | Liliaceae > Allium |
Sibling taxa | ||
Synonyms | A. douglasii var. columbianum | |
Name authority | (Ownbey & Mingrone) P. M. Peterson: Syst. Bot. 13: 211. (1988) | Linnaeus: Sp. Pl. 1: 301. (1753) |
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