Eriogonum luteolum

Greene

Pittonia 3: 200. 1897.

IllustratedEndemic
Synonyms: Eriogonum vimineum var. luteolum (Greene) S. Stokes
Treatment appears in FNA Volume 5. Treatment on page 420. Mentioned on page 414, 415, 422.

Herbs, erect or prostrate to spreading, 0.5–6 dm, glabrous or occasionally tomentose, greenish to reddish. Stems: aerial flowering stems prostrate to erect, 0.2–2 dm, glabrous or occasionally tomen-tose. Leaves basal or basal and cauline; basal: petiole 1–8 cm, floccose, blade oblong-ovate, reniform, or rounded to cordate, 0.5–5 × 0.5–3.5 cm, densely white-tomentose abaxially, floccose or glabrous and reddish or greenish adaxially; cauline: petiole 0.5–3 cm, floccose, blade cordate to reniform or orbiculate, 0.5–3 × 0.5–3 cm, similar to basal blade. Inflorescences cymose, occasionally distally uniparous due to suppression of secondary branches, open, 2–50 × 3–40 cm; branches glabrous or occasionally tomentose; bracts 1–3(–4) × 1–2 mm. Peduncles absent or erect, straight, slender, 0.1–0.5 cm, glabrous. Involucres terminal at tips of slender branchlets proximally or appressed to branches, cylindric or occasionally turbinate, 2–4 × 1.5–2.5 mm, glabrous or rarely floccose; teeth 5, erect, 0.3–0.5 mm. Flowers 1–2.5 mm; perianth white to rose or yellow, glabrous; tepals monomorphic, obovate; stamens included, 1–1.5 mm; filaments glabrous. Achenes light brown, 3-gonous, 1–2 mm.

Discussion

Varieties 4 (4 in the flora).

Selected References

None.

Key

1 Plants prostrate to spreading, 0.5-3 dm; involucres 3-4 mm, often terminal on elongated branchlets; leaves basal and cauline; serpentine soil; w Alameda and s Marin counties, California Eriogonum luteolum var. caninum
1 Plants erect, 2-6 dm; involucres 2-3.5 mm, appressed to inflorescence branches; leaves basal, sometimes also cauline; serpentine or granitic soils; San Mateo, Santa Clara, and Mariposa counties, California, n to sw and sc Oregon > 2
2 Involucres 2-3 mm; flowers 2-2.5 mm; granitic soils; Sierra Nevada, Alpine and Tuolumne counties, California Eriogonum luteolum var. saltuarium
2 Involucres 3-3.5 mm; flowers 1-2 mm; serpentine soils; Coast Ranges and lower foothills of Sierra Nevada, San Mateo, Santa Clara, and Mariposa counties, California, n to sw and sc Oregon > 3
3 Flowers 1.8-2 mm; Coast Ranges, w California from San Mateo and Santa Clara counties n to sw and sc Oregon Eriogonum luteolum var. luteolum
3 Flowers 1-1.5(-1.8) mm; e California from Mariposa County to Plumas County Eriogonum luteolum var. pedunculatum