[Onions: The Genus Allium East of the Cascade Mountains of Oregon and Washington]

Columbian Onion

Allium columbianum

Synonym: Allium douglasii var. columbianum

Flower and thickened scape below the umbel of Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum)

A close-up sideview of the thickened scape at the base of the inflorescence and a sideview of a flower of Columbian onion as seen on sandy slopes above the Little Spokane River, Little Spokane River Natural Area.........May 23, 2010.

Flower of Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum) Photo at right shows a close-up of the bumpy surface of the ovary of columbian onion as seen in shallow alkaline basins along the old highway to the southwest of Fishtrap Lake in eastern Washington.........June 2, 2008.
Characteristics:

Douglas' onion is an attractive wildflower with 2 basal leaves and a single leafless scape giving rise to a cluster of flowers at its tip. The stem is usually held higher than the leaves. The leaves are either convex in cross section and 2-8 mm wide or strongly flattened and up to 15 mm wide. The leaves usually persist until flowering. The scape is usually 20-30 cm high.

Two or three broadly ovate bracts with short-pointed tips subtend the umbel. The bracts are 5-7 nerved. The scape is thickened directly below the umbel (and bracts) but is not constricted. The umbel is several to many-flowered with individual flowers on thin pedicels which are 2-3 times longer than the tepals. The 6 tepals range from 6-10 mm long and are narrowly lanceolate with pointed tips. The coloration is pink or rarely white. The midribs of the tepals are prominent. The stamens are as long as or longer than the perianth with oblong, obtuse, or acute anthers.


Varieties:

variety columbianum: Leaves narrow, channeled and often not curved. Scape thickened below the umbel but not constricted. Plants along the Washington & Idaho state line from Kootenai to Idaho Counties Idaho through Spokane County, Washington to northern Whitman County in southeastern Washington. Also found in Sander County, Montana.

varitey constrictum: Leaves narrow, channeled and often not curved. Scape thickened below the umbel but constricted between the umbel and the swollen upper part of the scape. Plants of Upper Grand Coulee, Grant County, WA.

variety douglasii: Leaves wide and flat, often curved. Scape not thickened below the umbel. Plants found from southern Whitman and central Walla Walla Counties in southeastern Washington south to Wheeler, Grant and eastern Umatilla Counties in Oregon.

variety nevii: Leaves narrow, channeled and often not curved. Scape not thickened below the umbel. Plants of the eastern slope of the Cascade Mts. from Kittitas County in Washington south to northern Oregon.


Habitat:

Grasslands, sagebrush desert, and ponderosa pine forests in shallow, winter wet soils.


Range:

Douglas' onion is found wholly east of the Cascade Mountains, from Kittitas County, WA east to Spokane County and south to northern and northeastern Oregon.


Columbian Onion: Allium columbianum

The photo above shows a close-up of the bumpy surface of the ovary of columbian onion as seen in shallow alkaline basins along the old highway to the southwest of Fishtrap Lake in eastern Washington..........June 2, 2008.

Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum) - Inflorescence of Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum) - Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum)

Columbian onion as seen on sandy slopes above the Little Spokane River, Little Spokane River Natural Area.........May 9, 2016.


Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum) - Columbian Onion: Allium columbianum (Synonym: Allium douglasii var. columbianum)

Columbian onion as seen at left on sandy slopes above the Little Spokane River, Little Spokane River Natural Area.........May 23, 2010. Note the two basal leaves which are much shorter than the scape and are channeled on the upper surface. The photo at right shows Columbian onion in bud along the Headquarters Trail at Turnbull National Wildlife Refuge.......May 8, 2019.

Inflorescence of Allium douglasii

This photo shows a close-up of the scape which thickens slightly just below the inflorescence (still enclosed here by the flower bud) of columbian onion as seen in shallow alkaline basins along the old highway to the southwest of Fishtrap Lake in eastern Washington........June 2, 2008.

Paul Slichter