Contr. W. Bot. 11: 15. 1903.
Herbs, erect or spreading, annual, 1–5(–7) dm, glabrous or infrequently 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.
Phenology: Flowering May–Nov.
Habitat: Sandy to clayey or gravelly washes, flats, and slopes, saltbush, greasewood, sagebrush, and mountain mahogany communities, pinyon and/or juniper woodlands
Elevation: 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).