Snow Mountain wild buckwheat

Eriogonum ursinum S. Watson var. nervulosum S. Stokes, Eriogonum, 114. 1936

Herbs, spreading, matted, synoecious, 0.2-1 × 1-3(-5) dm, tomentose. Stems: caudex spreading; aerial flowering stems erect or nearly so, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, 0.2-0.6(-1) dm, tomentose. Leaves in compact basal rosettes; petiole 0.5-1 cm; blade broadly ovate, 0.4-0.8(-1) × 0.5-1 cm, densely white- to brownish-tomentose abaxially, thinly floccose or glabrous and green adaxially, margins plane to slightly revolute. Inflorescences subcapitate, 0.5-1.5 × 1-2 cm; branches tomentose; bracts 3-6, leaflike, lanceolate, 0.3-0.6 × 0.1-0.3 mm. Involucres 1 per node, turbinate, 3-4 × 2-3 mm, villous; teeth 6-8, erect, 0.4-0.8 mm. Flowers 3.5-5.5 mm, including 0.5-0.8 mm stipelike base; perianth white to ochroleucous, becoming pinkish rose or deep red, glabrous; tepals monomorphic, obovate; stamens exserted, 4-5 mm; filaments pilose proximally. Achenes light brown, 4.5-5 mm, glabrous.

Flowering May-Oct. Serpentine slopes and outcrops, mixed grassland communities, oak and conifer woodlands; of conservation concern; 300-2100 m; Calif.

Eriogonum nervulosum is found infrequently in small, widely scattered populations in the southern half of the North Coast Ranges. There are six known locations, and no doubt more remain to be found. Except for a Sonoma County site, the plants are found on ridges that separate Colusa and Lake counties, from Snow Mountain in the north to southwest of Clear Lake in the south. The species is found also in the Confusion Canyon area south and west of the lake. It is an ideal rock-garden introduction, although it grows only on grayish or reddish-brown serpentine soils in the wild.