Allium rhizomatum |
Allium bisceptrum |
|
---|---|---|
spreading wild onion |
twincrest onion |
|
Bulbs | solitary, not basally clustered, replaced annually by new bulbs borne terminally on rhizome; rhizomes 1–3, conspicuous, slender, 2–3 cm, scaly; parent bulbs persisting, often not collected, oblique-ovoid, 1–2.5 × 1 cm; outer coats enclosing parent bulbs, grayish, lacking cellular reticulation, membranous, without fibers; inner coats white or hyaline, cells obscure, ± quadrate. |
1–7+, commonly producing either cluster of stalked, basal bulbels or filiform rhizomes to 1 dm, terminated by bulbels, rhizomes generally lost when specimens are collected, ovoid, 1–2 × 0.6–1.8 cm; outer coats enclosing 1 or more bulbs, light brown to gray, membranous, obscurely cellular-reticulate, cells rectangular, walls minutely sinuous, vertical, varying to irregular, all sinuous, without fibers; inner coats white to pink, cells obscure, quadrate. |
Leaves | persistent, green at anthesis, 2–3, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, not falcate, 20–35 cm × 2–3 mm, margins entire. |
persistent, green at anthesis, 2–5, basally sheathing, sheaths not extending much above soil surface; blade solid, flat, broadly channeled, 8–30 cm × 1–13 mm, margins entire. |
Scape | solitary, erect, solid, terete, 20–30 cm × 1–3 mm. |
persistent, solitary or clustered 1–3, erect, solid, terete, 10–30(–40) cm × 1–5 mm. |
Umbel | persistent, erect, loose, 5–15(–22)-flowered, globose to hemispheric, bulbils unknown; spathe bracts persistent, 2, 3-veined, ovate to lance-ovate, ± equal, apex acute. |
persistent, erect, loose, 15–40-flowered, globose, bulbils unknown; spathe bracts persistent, 2, 3–4-veined, ovate to lanceolate, ± equal, apex acuminate. |
Flowers | stellate, 6–9 mm; tepals erect, pink with purplish or pinkish midveins, oblong to lanceolate, slightly carinate basally, ± equal, becoming papery in fruit, margins entire, apex acute to acuminate; stamens included; anthers yellow or pink; pollen yellow or white; ovary crestless, 3-grooved with thickened ridge on either side of groove; style linear, shorter than stamens; stigma capitate, scarcely thickened, unlobed; pedicel 10–20(–50) mm. |
stellate, 7–10 mm; tepals spreading, lilac to white, lanceolate, ± equal, becoming papery in fruit, not carinate, margins entire, apex acuminate, not involute; stamens included; anthers purple; pollen yellow; ovary conspicuously crested; processes 6, central, distinct, flattened, triangular, margins papillose-denticulate; style included, linear, ± equaling stamens; stigma capitate, unlobed; pedicel 10–20 mm, often becoming flexuous and deflexed in fruit. |
Seed | coat shining; cells smooth. |
coat shining; cells each with minute, central papilla. |
2n | = 28. |
= 14, 28. |
Allium rhizomatum |
Allium bisceptrum |
|
Phenology | Flowering Jul–Sep. | Flowering May–Jul. |
Habitat | Dry, usually grassy areas | Meadows and aspen groves, less commonly on open slopes in mountains |
Elevation | 1200–2200 m (3900–7200 ft) | 1100–3000 m (3600–9800 ft) |
Distribution |
AZ; NM; TX; Mexico
|
AZ; CA; ID; NM; NV; OR; UT
|
Discussion | Allium rhizomatum has often been included within the Mexican species A. glandulosum. This reduction is unwarranted. The perianth of A. rhizomatum is pale, with the color mainly confined to the midribs. Additionally, the species can be distinguished by its 3-lobed, apically 3-grooved ovary and lack of sepal glands. Allium glandulosum has a red perianth, an apically rounded ovary, and sepal glands. The nectar produced from these glands does not show in herbarium specimens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Two varieties of Allium bisceptrum have been recognized. Where their ranges overlap (central Utah and central Nevada), the putative varieties cannot be distinguished confidently except by chromosome number. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 26. | FNA vol. 26, p. 256. |
Parent taxa | Liliaceae > Allium | Liliaceae > Allium |
Sibling taxa | ||
Synonyms | A. bisceptrum var. palmeri, A. bisceptrum var. utahense, A. palmeri | |
Name authority | Wooton & Standley: Contr. U.S. Natl. Herb. 16: 114. (1913) | S. Watson: Botany (Fortieth Parallel), 351, plate 37, figs. 1–3. (1871) |
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