Allium validum is a species of flowering plant commonly called swamp onion, wild onion, Pacific onion, or Pacific mountain onion. It is native to the Cascade Range, to the Sierra Nevada, the Rocky Mountains, and other high-elevation regions in California, Oregon, Washington, Nevada, Idaho and British Columbia. It is a perennial herb and grows in swampy meadows at medium and high elevations.
Allium cernuum, known as nodding onion or lady's leek, is a perennial plant in the genus Allium. It grows in open areas in North America.
Allium unifolium, the one-leaf onion or American garlic, is a North American species of wild onion. It is native to the coastal mountain ranges of California, Oregon, and Baja California. It grows on clay soils including serpentine, at elevations up to 1100 m.
Allium crispum is a species of wild onion known by the common name crinkled onion. It is endemic to California, where it grows along the Central Coast in the Coast Ranges and in the Santa Monica Mountains, often in clays and serpentine soils. It is a perennial herb that is typically found in the foothill woodlands and valley grasslands of California.
Allium amplectens, the narrowleaf onion, is a species of flowering plant. It is a onion native to the west coast of the United States, in Oregon, Washington State and California, also British Columbia in Canada. It grows in woods and especially in clay and serpentine soils.
Allium campanulatum is a species of wild onion known by the common name dusky onion or Sierra onion. This is a flowering plant native to the western United States from southeastern Washington and northern Oregon to southern California, and western Nevada. The dusky onion grows in foothills and mountains, especially in dry areas, such as chaparral habitats.
Allium obtusum is a species of wild onion known by the common name red Sierra onion or subalpine onion. It is native to eastern California and western Nevada. It is a common plant in the granite foothills and mountains of the Sierra Nevada and southern Cascade Range, from Tulare County to Siskiyou County, from elevations of 800 to 3,500 metres. In Nevada, it is reported only from Washoe County in the northwestern part of the state.
Allium platycaule is a species of wild onion known as broadstemmed onion or flat-stem onion. It is native to northeastern California, south-central Oregon and northwestern Nevada. It is found on slopes of elevations of 1500–2500 m.
Allium shevockii is a rare species of wild onion known by the common name Spanish Needle onion. It is found only in a limited area in the southern Sierra Nevada of California.
Allium monticola is an uncommon species of wild onion known by the common name San Bernardino Mountain onion. It is endemic to southern California, where it is found in the Transverse Ranges and the northernmost section of the Peninsular Ranges. It has been reported from San Bernardino, Los Angeles, Orange, Ventura and Santa Barbara Counties.
Allium fibrillum is a North American species of wild onion known by the common names Blue Mountain onion and Cuddy Mountain onion. It is native to the northwestern United States from eastern Washington and Oregon through Idaho to Montana. It is a perennial herb.
Allium constrictum, the Grand Coulee onion, is a plant species endemic to the US State of Washington. It is known from only three counties in the east-central part of the state: Douglas, Grant, and Lincoln. It grows on dry, sandy soils at elevations of 300–500 m.
Allium macrum, the rock onion, is an American species of wild onion native to the eastern and central parts of the US States of Oregon and Washington. It grows on gravelly soils at elevations up to 1400 m. It is a perennial herb.
Allium madidum, common name mountain swamp onion, is a plant species native to the west-central Idaho, southern Washington and eastern Oregon. It grows in wet meadows at elevations of 1100–2000 m.
Allium robinsonii, the Columbia River onion or Robinson's onion, is a rare plant species native to the US States of Washington and Oregon, although some studies suggest that the Oregon populations may now be extinct. The species has been reported from five counties in Washington and five in Oregon. It is found in sand and gravel deposits along the lower Columbia River and some of its tributaries, usually at elevations less than 200 m. The species is also cultivated as an ornamental in other regions, including in Europe.
Allium scilloides, called the fragile onion, is a plant species endemic to the US State of Washington. It has been reported from only 4 counties, all on the eastern side of the Cascade Range: Klickitat, Kittitas, Yakima and Grant. It grows on barren, gravelly slopes at elevations of 300–1300 m. The species is sometimes cultivated in other regions as an ornamental.
Allium tolmiei is a plant species native to Idaho, eastern and central Oregon, southeastern Washington, northwestern Nevada and northeastern California. It occurs on mountains and scrublands at elevations of 1,300–9,200 feet (400–2,800 m). It was discovered by and named for Dr. William Fraser Tolmie.
Allium douglasii, the Douglas onion, is a plant species native to northeastern Oregon, eastern Washington, and northern Idaho. It grows in shallow soils at elevations of 400–1,300 m (1,300–4,300 ft).
Allium nevii, known by the common name Nevius' onion or Nevius' garlic, is a plant species native to central Washington and north-central Oregon in the United States. It grows in wet meadows and along stream banks at elevations up to 2000 m.
Allium crenulatum, common name Olympic onion, is a plant species native to Oregon, Washington, and British Columbia. It grows in the Cascades, the Coast Ranges, the Olympic Mountains, the Wenatchee Mountains, and the mountains on Vancouver Island. There is one report from Alabama, but this needs verification. The species grows on talus slopes and in alpine tundra at elevations of 600–2500 m.
