Plants herbs, erect, infrequently polygamodioecious, 2–4 (7) dm tall, 2–5 dm across; floccose or glabrous; stems with caudex spreading, the aerial flowering stems erect, slender or stout, hollow, often slightly fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, 1–5 dm long, floccose or glabrous; leaves basal, occasionally in rosettes, the petioles 4–10 (15) cm long, tomentose, the blades lanceolate or ovate to deltoid, (2) 7–25 cm long, (0.7) 1–8 cm wide, densely white-lanate to tomentose abaxially, less so to glabrate and greenish adaxially, the margins entire, plane; inflorescences umbellate or compound-umbellate, 3–20 cm long and wide, the branches floccose or glabrous, the bracts 3–several, foliaceous or semi-foliaceous at proximal nodes, linear to linear-lanceolate, 1–3 (6) cm long, scalelike distally, usually 1–5 mm long, 0.5–3 mm wide; involucres 1 per node, turbinate-campanulate to campanulate, 6–10 mm long, 4–10 mm wide, sparsely to densely lanate, weakly glandular-puberulent, or glabrous, the teeth (5) 7– 10, usually not lobelike, erect to weakly reflexed, 2–4 mm long; flowers 5–6 mm long, including a 0.7–1.5 mm long stipelike base, the perianth pale to bright yellow, occasionally ochroleucous, glabrous, the tepals monomorphic, oblong to oblong-ovate, the stamens slightly exserted, 4–8 mm long, the filaments pilose proximally; achenes light brown, 5–6 mm long, glabrous except for sparsely pubescent beak.
- Leaf blades lanceolate; Chelan, Kittitas, Okanogan, and Yakima cos., Washington: Eriogonum compositum var. lancifolium
- 1 Leaf blades ovate to deltoid; widespread.
- Involucres sparsely to densely lanate; n California, wc Idaho, Oregon, and Washington : Eriogonum compositum var. compositum
- Involucres glabrous or weakly glandular-puberulent; wc Idaho, ne Oregon, and e Washington : Eriogonum compositum var. leianthum.
Eriogonum compositum var. compositum: Plants 4–7 dm tall; aerial flowering stems stout, often fistulose, 2–5 dm long, usually glabrous, rarely floccose; leaf blades ovate to deltoid, (2) 7–25 cm long, 2–8 cm wide; involucres sparsely to densely lanate; flowers 5–6 mm long, the perianth pale to bright yellow. 2n = 40.
Flowering Apr-Jul. Sandy to gravelly flats and slopes, mixed grassland and sagebrush communities, oak and montane conifer woodlands; 30–2500 m.