Tapertip Onion, Taper-tip Onion, Hooker's Onion: Allium accuminatum (Synonyms: Allium acuminatum var. acuminatum, Allium acuminatum var. cuspidatum, Allium cuspidatum) - 3-4 leaves are narrow, linear and flexuous, shorter than the scape. Outer tepals 10-12 mm long. Flowers rose-purple, pink or sometimes white. Ovaries slightly crested.
Narrow-leaf Onion, Slim-leaf Onion: Allium amplectens (Synonyms: Allium acuminatum var. gracile, Allium attenuifolium, Allium attenuifolium var. monospermum, Allium monospermum, Allium occidentale, Allium serratum)- 3-4 leaves are narrow, linear and flexuous, shorter than the scape. Outer tepals are 5-11 mm long. Flowers are white or pink.
Anceps Onion, Kellogg's Onion: Allium anceps - 2 leaves flattened and 4-5 mm wide and 8-12 cm long. Scape 6-10 cm high, distinctly winged above. Umbel 15-25 flowered. Tepals 8-12 mm long, rose colored with deep rose-purple midveins. Stamens about equal to the tepals. Ovary with 6 broad crests.
Two-stemmed Onion, Twincrest Onion, Twin-crest Onion: Allium bisceptrum (Synonym: Allium bisceptrum var. bisceptrum) - Leaves exist at blooming. Tepals 5-7 mm long, white , lilac or pale pink in color. Scape 20-30 cm high.
Brandegee's Onion: Allium brandegei (Synonyms: Allium brandegeei, Allium diehlii, Allium minimum, Allium tribracteatum) - Leaves usually longer than the scape. Scape is 3-10 cm high. Ovary rarely crested.
Sierra Onion: Allium campanulatum - Leaves wither by blooming. Scape less than 15 cm high. Tepals 7-8 mm long, purplish with a purple blotch near the base. Ovary with 6 prominent crests.
Nodding Onion: Allium cernuum (Synonyms: Allium allegheniense, Allium cernuum var. cernuum, Allium oxyphilum, Allium recurvatum) - Two leaves concave-convex in cross-section to flattened and shorter than the scape. Scape round in cross-section. The umbel is nodding. Tepals white or pink, 4-6 mm long. Ovary crested with 6 thin, flattened, entire or toothed processes.
Columbian Onion: Allium columbianum (formerly Allium douglasii var. columbianum) -
Scalloped Onion, Olympic Onion: Allium crenulatum (Synonyms: Allium cascadense, Allium vancouverense, Allium watsonii) - The 2 broad, flat leaves are down-curved and longer than the scape. Scapes flattened and winged. Tips of the tepals are generally not in-turned. Stamens less than 3/4 the length of the tepals. Common from the Cascade Mts west, this is found east of the Cascades only in the Wenatchee Mts.
Blue Mt. Onion: Allium dictuon - Two flattened to v-shaped leaves that are shorter than the scape. Scape round in cross-section. Tepals 10-15 mm long, bright pink. Ovary & capsule not crested.
Douglas' Onion: Allium douglasii (Synonym: Allium douglasii var. douglasii) - Scape usually equal to or longer than the leaves. Tepals 7-8 mm long and white or pink. Stamens equal to or longer than the tepals.
Cuddy Mountain Onion, Jone's Onion, Fringed Onion: Allium fibrillum - Scape cylindrical. Leaves concave-convex. Tepals white. Stamens shorter than the tepals.
Geyer's Onion: Allium geyeri var. geyeri (Synonyms: Allium dictyotum, Allium funiculosum, Allium pikeanum) - Leaves generally 3 or more, up to 3 mm wide and to 30 cm long. Scapes 20-60 cm high. Rose-colored flowers often mixed with pink-tinged bulblets. The stamens are shorter than the tiny, triangular tepals.
Bulbil Onion: Allium geyeri var. tenerum (Synonyms: Allium arenicola, Allium fibrosum, Allium geyeri ssp. tenerum, Allium geyeri var. graniferum, Allium rubrum, Allium rydbergii, Allium sabulicola) -
Lemmon's Onion: Allium lemmonii - Scape strongly flattened and winged, from 5-15 cm high. Tepals 5-9 mm long, pale pink or white with green or pinkish midvein. Stamens equal to or slightly longer than the tepals. Ovary generally crestless.
Rock Onion: Allium macrum (Synonym: Allium equicaeleste) - Scape cylindrical. The slender leaves are concave-convex and longer than the scape. The tepals are white to pale reddish with a green mid-rib. Stamens equal to or longer than the tepals.
Swamp Onion: Allium madidum - The 2 leaves are stiff, not flexuous and about equal in height to (or longer than) the scape. The scape is cylindrical in x-section.
Nevada Onion: Allium nevadense - One semisolid leaf, longer than the scape and tending to coil at the tip and breaking off with age. Tepals at least 8 mm long. Ovary & capsule strongly crested. Desert habitats.
Nevius' Garlic, Nevius' Onion: Allium nevii (Synonym: Allium douglasii var. nevii) -
Dwarf Onion, Small Onion: Allium parvum (Synonyms: Allium modocense, Allium parvum var. parvum, Allium tribracteatum) - Scape flattened and winged. Tepals 7-10 mm long. Stamens 2/3 as long as tepals.
Broadstem Onion, Flatstem Onion: Allium platycaule - Flattened scape and leaves. Tepals narrow.
Many-flowered Onion: Allium pleianthum - Leaves strongly flattened and 3-5 mm wide. Scape strongly flattened, usually less than 10 cm high. Tepals 10-12 mm long, pale pink to lavender. Found only in Wheeler County, OR.
Punctate Onion: Allium punctum (Synonym: Allium parvum var. punctum) - The 2 leaves are much longer than the scape, striaght or slighly arched, the blades 2-3 mm wide. Scape 3-5 cm long, flattened but not winged. Umbel 12-20 flowered. The tepals are 8-10 mm long, and a deep rose-purple. Ovary with 3 wide double crests.
Robinson's Onion: Allium robinsonii - Stamens 1/2 to 3/4 the length of the tepals. Tepals 7-12 mm long, white to pale pink. Along banks of Columbia River.
Chives: Allium schoenoprasum - Two hollow leaves that are shorter than the scape. Ovary & capsule not crested.
Fragile Onion, Scilla-like Onion: Allium scilloides - 1-2 leaves are broad and flat. Stems flattened. Margins of the white, pink or red tepals are not in-turned. Stamens shorter than the tepals.
Tolmie's Onion: Allium tolmiei var. tolmiei (Synonyms: Allium cusickii, Allium pleianthum, Allium tolmiei var. platyphyllum) - The 1-2 leaves are broad, flat, and equal to or shorter than the scape. Scapes flattened and winged. Tips of the tepals are strongly in-turned. Stamens less than 3/4 the length of the tepals.
Pacific Onion, Pacific Swamp Onion, Tall Swamp Onion: Allium validum - Leaves several, broad (4-11 mm) and shorter than the scape. Tepals pink, 8-10 mm long. Stamen and style greater than the tepals. Ovary and capsule without crests.