Fox-tail wild buckwheat

Eriogonum umbellatum Torrey var. polypodum (Small) S. Stokes; E. ursinum S. Watson var. venosum S. Stokes ex Smiley

Herbs, matted, polygamo-dioecious, 0.5-1.5 × 1-4(-5) dm, mostly tomentose. Stems: caudex spreading; aerial flowering stems erect, slender, solid, not fistulose, arising at nodes of caudex branches and at distal nodes of short, nonflowering aerial branches, 0.5-1.5 dm, mostly tomentose. Leaves in congested basal rosettes; petiole 0.1-0.6(-1) cm, usually tomentose; blade ovate, 0.2-1 × 0.1-0.6(-0.8) cm, densely tomentose on both surfaces but adaxial surface soon glabrous and green, margins entire, plane. Inflorescences capitate, 0.5-2 cm wide, those with pistillate flowers becoming umbellate in fruit, 1.5-3 × 2-3 cm; branches tomentose to floccose; bracts 4-6 proximally, usually leaflike, 0.2-0.8 cm, absent immediately below involucre. Involucres 1 per node, turbinate, (2-)2.5-3.5(-4) × 2-3 mm, tomentose; teeth 5-7, spreading, 1-2 mm. Flowers 2.5-3.5 mm, including 0.2-0.4 mm stipelike base; perianth chalky white, glabrous; tepals monomorphic, oblong to narrowly obovate; stamens exserted, 1-2 mm; filaments pilose proximally. Achenes light brown, 3-3.5 mm, glabrous.

Flowering Jul-Sep. Sandy to gravelly granitic flats, slopes, and outcrops, high-elevation sagebrush communities, subalpine and alpine conifer woodlands; (2400-)2800-3500(-3700) m; Calif.

Eriogonum polypodum is found in the southern Sierra Nevada in Fresno and Tulare counties, with the bulk of its scattered populations west of Mt. Whitney. The chalky white flowers are distinctive, especially when observed in the field, and unique in subg. Oligogonum.