Tall buckwheat is also known as rush-stemmed buckwheat. It is a large, sturdy wildflower, with large lanceolate or arrowhead-shaped basal leaves, one to several erect and hollow stems with no cauline leaves, and a two to three-branched open cyme. The leaves may be somewhat tomentose, but the plants typically appear to be mostly green. The leaves range in length from 7-15 cm long, with the petiole about equal in length to the blade.
The inflorescence is large, branched, and open. The flowers are typically creamy, pink in the bud, and aging to a red color. Typical tall buckwheats range from 30-120 cm tall. The involucres are either solitary or in small terminal clusters. The narrowly conical involucres are glabrous with prominent nerves, and they measure about 3 mm long. The terminal lobes of the involucre are shallowly rounded with ciliate margins. The perianth is 2-3 mm long with a hairy exterior surface.
This is one of the easiest of the Eriogonums to identify in the Pacific Northwest due to its large stature, large basal leaves, and lack of leaves on the stems.
Tall buckwheat is found from the sagebrush desert to open mountain slopes below 7000 feet.
Tall buckwheat may be found from north-central Washington (Okanogan County) south along the eastern Cascade slope to northeast California, found sparsely south to Mono County, California, and east to Idaho and western Nevada.