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Sanborn's onion

Bulbs

1–3, not clustered on stout, primary rhizome, ovoid, 1–2.5(–3) × 1.2–2 cm;

outer coats enclosing 1 or more bulbs, dark reddish brown, chartaceous, lacking cellular reticulation or cells arranged in 2–3 rows distal to roots, ± quadrate, without fibers;

inner coats light brown or white, cells obscurely quadrate.

1–50+, ovoid, 0.2–1.5 × 0.2–1 cm;

outer coats surrounding numerous, very dark purple bulbels, usually white or greenish, membranous, sometimes breaking into ± parallel, fibrous strips;

inner coats white, cells obscure, quadrate.

Leaves

persistent, withering from tip by anthesis, 1, basally sheathing, sheath never extending much above soil level;

blade solid, terete, 30–45 cm × 2–4 mm.

persistent, 2–5, sheathing 1/3–1/2 scape;

blade solid, flat or channeled, carinate, 15–40 cm × 2–5(–7) mm, margins entire.

Scape

persistent, solitary, erect, ± solid, terete, 18–60 cm × 2–3 mm.

persistent, solitary, erect, ± solid, 25–90 cm × 1–4 mm.

Umbel

persistent, erect, compact, 18–190-flowered, hemispheric to globose, bulbils unknown;

spathe bracts persistent, 4, 3-veined, ovate, ± equal, apex long-acuminate.

persistent, erect, very dense, 80–200-flowered, globose, bulbils unknown;

spathe bracts caducous, 2, 7–12-veined, lanceolate, ± equal, apex narrowed to beak, beak to 2 cm.

Flowers

campanulate, 5–9 mm;

tepals erect, white to pink with darker midveins, unequal, becoming papery in fruit, margins entire or irregular to erose, apex acute or acuminate to long-acuminate;

outer tepals lanceolate to ovate, reflexed at tip;

inner 1/4–1/3 longer than outer, ovate to broadly ovate;

stamens exserted;

anthers yellow or purple;

pollen yellow or white;

ovary crested;

processes 6, prominent, erect, ± triangular, margins entire;

style linear, equaling stamens;

stigma capitate, obscurely to distinctly 3-lobed, lobes erect or spreading, ± stout;

pedicel 8–22 mm.

campanulate, 4–7 mm;

tepals erect, purple, or inner with broad whitish margins and purple midvein, oblong to ovate, ± equal, becoming keeled and ± rigid in fruit, margins entire, apex acute to obtuse;

stamens included;

filaments: outer unlobed, inner with 2 prominent teeth on either side of anther, teeth 2–3 times anther-bearing portion, usually papillose to ciliate;

anthers yellow or purple;

pollen light yellow to white;

ovary crestless;

style linear, ± equaling anther-bearing portion of stamens;

stigma capitate, unlobed;

pedicels 5–30 mm, outer much shorter than inner.

Seed

coat dull;

cells minutely roughened.

coat dull;

cells each with central papilla.

Allium sanbornii

Allium rotundum

Phenology Flowering May–Jul.
Habitat Disturbed fields and roadsides
Distribution
from USDA
Calif and Oreg
[WildflowerSearch map]
[BONAP county map]
from FNA
MI; c Europe; s Europe [Introduced in North America]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Allium rotundum is native to central and southern Europe. It is reported as established in southern Michigan, and is to be expected elsewhere in the Great Lakes region.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Stigma obscurely 3-lobed; tepal apex acute; anthers mostly yellow; flowering late Jun–Aug.
var. sanbornii
1. Stigma distinctly 3-lobed; tepal apex acuminate to long-acuminate; anthers mostly purple; flowering late Jun–Jul.
var. congdonii
Source FNA vol. 26, p. 248. FNA vol. 26, p. 244.
Parent taxa Liliaceae > Allium Liliaceae > Allium
Sibling taxa
A. aaseae, A. abramsii, A. acuminatum, A. ampeloprasum, A. amplectens, A. anceps, A. atrorubens, A. bigelovii, A. bisceptrum, A. bolanderi, A. brandegeei, A. brevistylum, A. burlewii, A. campanulatum, A. canadense, A. cepa, A. cernuum, A. columbianum, A. constrictum, A. coryi, A. cratericola, A. crenulatum, A. crispum, A. cuthbertii, A. denticulatum, A. diabolense, A. dichlamydeum, A. dictuon, A. douglasii, A. drummondii, A. elmendorfii, A. falcifolium, A. fibrillum, A. fimbriatum, A. fistulosum, A. geyeri, A. gooddingii, A. haematochiton, A. hickmanii, A. hoffmanii, A. howellii, A. hyalinum, A. jepsonii, A. kunthii, A. lacunosum, A. lemmonii, A. macropetalum, A. macrum, A. madidum, A. membranaceum, A. monticola, A. munzii, A. neapolitanum, A. nevadense, A. nevii, A. nigrum, A. obtusum, A. oleraceum, A. paniculatum, A. parishii, A. parryi, A. parvum, A. passeyi, A. peninsulare, A. perdulce, A. platycaule, A. plummerae, A. praecox, A. punctum, A. rhizomatum, A. robinsonii, A. rotundum, A. runyonii, A. sativum, A. schoenoprasum, A. scilloides, A. serra, A. sharsmithiae, A. shevockii, A. simillimum, A. siskiyouense, A. speculae, A. stellatum, A. textile, A. tolmiei, A. tribracteatum, A. tricoccum, A. triquetrum, A. tuberosum, A. tuolumnense, A. unifolium, A. validum, A. victorialis, A. vineale, A. yosemitense
A. aaseae, A. abramsii, A. acuminatum, A. ampeloprasum, A. amplectens, A. anceps, A. atrorubens, A. bigelovii, A. bisceptrum, A. bolanderi, A. brandegeei, A. brevistylum, A. burlewii, A. campanulatum, A. canadense, A. cepa, A. cernuum, A. columbianum, A. constrictum, A. coryi, A. cratericola, A. crenulatum, A. crispum, A. cuthbertii, A. denticulatum, A. diabolense, A. dichlamydeum, A. dictuon, A. douglasii, A. drummondii, A. elmendorfii, A. falcifolium, A. fibrillum, A. fimbriatum, A. fistulosum, A. geyeri, A. gooddingii, A. haematochiton, A. hickmanii, A. hoffmanii, A. howellii, A. hyalinum, A. jepsonii, A. kunthii, A. lacunosum, A. lemmonii, A. macropetalum, A. macrum, A. madidum, A. membranaceum, A. monticola, A. munzii, A. neapolitanum, A. nevadense, A. nevii, A. nigrum, A. obtusum, A. oleraceum, A. paniculatum, A. parishii, A. parryi, A. parvum, A. passeyi, A. peninsulare, A. perdulce, A. platycaule, A. plummerae, A. praecox, A. punctum, A. rhizomatum, A. robinsonii, A. runyonii, A. sanbornii, A. sativum, A. schoenoprasum, A. scilloides, A. serra, A. sharsmithiae, A. shevockii, A. simillimum, A. siskiyouense, A. speculae, A. stellatum, A. textile, A. tolmiei, A. tribracteatum, A. tricoccum, A. triquetrum, A. tuberosum, A. tuolumnense, A. unifolium, A. validum, A. victorialis, A. vineale, A. yosemitense
Subordinate taxa
A. sanbornii var. congdonii, A. sanbornii var. sanbornii
Name authority Alph. Wood: Proc. Acad. Nat. Sci. Philadelphia 20: 171. (1868) Linnaeus: Sp. Pl. ed. 2, 1: 423. (1762)
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