Allium crenulatum |
Allium cepa |
|
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Olympic onion, scalloped onion |
cultivated onion, garden onion |
|
Bulbs | 1–6+, replaced annually with new bulbs borne terminally on rhizomes; rhizomes 1–2, secondary, short; parent bulb disappearing by anthesis except for still-functional roots and shriveled bulb coat, oblique-ovoid, 1–2 × 0.8–1.8 cm; outer coats not or only partially enclosing bulbs, brown to gray-brown, membranous, lacking cellular reticulation or cells arranged in only 2–3 rows distal to roots, ± quadrate, without fibers; inner coats white, cells very obscurely quadrate or not visible. |
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, (1–)2, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, falcate, 10–33 cm × 1.5–10 mm, margins sometimes minutely denticulate. |
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, winged distally, wings frequently crenulate proximal to umbel, 5–15 cm × 1–5 mm. |
persistent, solitary, erect, fistulose, inflated below middle, 30–100 cm × 3–20 mm. |
Umbel | persistent, erect, compact, 10–25-flowered, conic to hemispheric, bulbils unknown; spathe bracts persistent, 2, 8–10-veined, lanceolate, ± 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 | campanulate, 6–12 mm; tepals erect, pinkish with deeper pink midveins, lanceolate, ± equal, becoming papery in fruit, margins entire, apex acute; stamens included; anthers yellow or purple; pollen yellow; ovary obscurely crested; processes 3, central, 2-lobed, minute, margins entire; style linear, equaling stamens; stigma capitate, scarcely thickened, unlobed; pedicel 6–16 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 crenulatum |
Allium cepa |
|
Phenology | Flowering late May–Jul. | Flowering Jun–Aug. |
Habitat | Talus slopes and clay soils, including serpentine, on bald summits and ridges | Disturbed sites adjacent to areas where cultivated |
Elevation | 600–2500 m (2000–8200 ft) | 0–500 m (0–1600 ft) |
Distribution |
OR; WA; BC
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AR; CA; KS; LA; MT; OR; TX; WA; cultivated in Europe; Asia
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Discussion | Allium crenulatum is known only from west of the Cascade Mountains from Vancouver Island to southwestern Oregon, in Jefferson Park, Oregon, and in the Wenatchee Mountains, central Washington. The disjunct populations of Allium crenulatum in western Oregon are markedly different among themselves and from the more typical representatives to the north. It has thus far proven impossible to draw meaningful taxonomic distinctions among these populations, hence we have followed historical precedent and have placed them all in a single, highly variable species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. 274. | FNA vol. 26, p. 244. |
Parent taxa | Liliaceae > Allium | Liliaceae > Allium |
Sibling taxa | ||
Synonyms | A. cascadense, A. vancouverense, A. watsonii | |
Name authority | Wiegand: Bull. Torrey Bot. Club 26: 135, plate 355, fig. 1. (1899) | Linnaeus: Sp. Pl. 1: 301. (1753) |
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