The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

American garlic, one-leaf onion

red Sierra onion, red Sierran onion

Bulbs

solitary, replaced annually by new bulbs borne terminally on secondary rhizome;

rhizomes 1–3, conspicuous, to 5 cm, smooth;

parent bulbs disappearing by anthesis except for still-functional roots and bulb coat, ovoid to oblique-ovoid, 1–2 × 0.8–1.5 cm;

outer coats not enclosing bulbs, pale brown, delicately cellular-reticulate, membranous, cells ± rectangular, without fibers;

inner coats white, cells obscure, ± transversely elongate, contorted.

1–5, not clustered on stout primary rhizome, ovoid, 1–2 × 0.8–1.8 cm;

outer coats enclosing 1 or more bulbs, brown, membranous, cellular-reticulate, cells quadrate, polygonal, or ± rectangular, ± transversely elongate, without fibers;

inner coats white, reticulation absent or cells obscure, ± quadrate.

Leaves

persistent, green or withering from tip at anthesis, 2–3, basally sheathing, sheaths not extending much above soil surface;

blade solid, flattened, sometimes carinate abaxially, ± falcate, 18–50 cm × 4–10 mm, margins entire.

usually deciduous with scape, withering from tip at anthesis, 1–2, basally sheathing, sheaths not extending much above soil surface;

blade solid, flat or broadly channeled, ± falcate, 5–22 cm × 0.5–14 mm, margins entire.

Scape

persistent, solitary, erect, solid, terete, 20–80 cm × 2–7 mm.

usually forming abcission layer and deciduous with leaves after seeds mature, frequently breaking at this level after pressing, solitary, erect, solid, terete, 2–17 cm × 0.5–2 mm.

Umbel

persistent, erect, loose, 15–35-flowered, hemispheric, bulbils unknown;

spathe bracts persistent, 2, 6–8-veined, lance-ovate to broadly ovate, ± equal, apex acuminate.

persistent, erect, compact, 6–65-flowered, hemispheric, bulbils unknown;

spathe bracts persistent, 2–3(–5), 5-8-veined, ovate, ± equal, apex abruptly acuminate to apiculate.

Flowers

stellate, 11–15 mm;

tepals spreading, bright pink or rarely white, obovate to ovate, unequal, becoming papery and connivent over capsule, margins entire, apex acute to obtuse or emarginate, inner shorter and narrower than outer;

stamens included;

anthers yellow or purple;

pollen yellow or gray;

ovary crestless, 3-grooved, with thickened ridge on either side of groove;

style linear, equaling stamens;

stigma capitate, scarcely thickened, unlobed or obscurely 3-lobed;

pedicel 15–40 mm.

campanulate, 4–12 mm;

tepals erect, white or pink with dark purplish midveins, lanceolate to oblong-elliptic, ± equal, becoming papery in fruit, margins entire, apex obtuse to acute;

stamens included;

anthers yellow or purple;

pollen yellow;

ovary crested;

processes 3, obscure to ± prominent, rounded, central, margins entire;

style linear, equaling stamens or longer;

stigma capitate, scarcely thickened, obscurely 3-lobed;

pedicel 2–14(–20) mm.

Seed

coat dull;

cells minutely roughened.

coat dull;

cells ± smooth.

2n

= 14.

Allium unifolium

Allium obtusum

Phenology Flowering May–Jun.
Habitat Moist, clay soils, including serpentine, usually along streams
Elevation 0–1100 m (0–3600 ft)
Distribution
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; NV
[WildflowerSearch map]
[BONAP county map]
Discussion

The long, relatively thick rhizomes that develop annually from the bulbs are very characteristic of Allium unifolium and almost unique in North America. Only A. glandulosum Link & Otto and A. rhizomatum Wooton & Standley have similar rhizomes, but these species are not closely related to A. unifolium.

Allium unifolium is known only from the Coast Ranges.

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

Varieties 2 (2 in the flora).

Allium obtusum is known only from the Sierra Nevada.

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

Key
1. Leaf blade 0.5–4 mm wide; umbels 6–20-flowered; tepals white with prominent, dark midveins, oblong-elliptic, apex obtuse.
var. obtusum
1. Leaf blade 2–14 mm wide; umbels 10–65-flowered; tepals pink with darker midveins, lanceolate, apex acute.
var. conspicuum
Source FNA vol. 26, p. 258. FNA vol. 26, p. 269.
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. 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. 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. 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. 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. obtusum var. conspicuum, A. obtusum var. obtusum
Synonyms A. grandisceptrum, A. unifolium var. lacteum
Name authority Kellogg: Proc. Calif. Acad. Sci. 2: 112, fig. 35. (1863) Lemmon: Pittonia 2: 69. (1890)
Web links