Herbs, erect or spreading, annual, 1-5(-7) dm, glabrous or infre-quently slightly floccose, greenish, grayish, or reddish. Stems: caudex absent; aerial flowering stems erect, solid, not fistulose, 0.3-1 dm, glabrous, infrequently slightly floccose proximally. Leaves basal; petiole 1-5 cm, floccose; blade elliptic to obovate or orbiculate, (0.5-)1-2.5(-3) × (0.5-)1-3 (3.5) cm, tomentose to hirsute abaxially, floccose or glabrous and greenish adaxially, margins plane. Inflorescences cymose to cymose-paniculate or racemose, open, 5-60 × 5-45 cm; branches glabrous; bracts 3, scalelike, 1-2(-4) × 1-2 mm. Peduncles ascending, curving, slender, 1-5 cm, glabrous. Involucres turbinate, (1.5-)2-3 × (1-)1.5-2.5 mm, glabrous; teeth 5, erect, 0.5-1 mm. Flowers 1-2.5 mm; perianth white to pale yellow, glabrous, pustulose proximally; tepals monomorphic, lanceolate to spatulate or ovate; stamens included, 1-1.8 mm; filaments glabrous. Achenes brown, lenticular, 2-2.5 mm, glabrous. 2n = 36.
Flowering May-Nov. Sandy to clayey or gravelly washes, flats, and slopes, saltbush, greasewood, sagebrush, and mountain mahogany communities, pinyon and/or juniper woodlands; 1300-2000 m; Calif., Nev., Oreg.
Eriogonum collinum is infrequent to locally common in the Lahontan Basin region of the Intermountain West in northeastern California (Lassen and Modoc counties), south-central Oregon (Lake County), and northwestern Nevada (Douglas, Humboldt, Lyon, Pershing, Storey, and Washoe counties).