88h. Eriogonum heermannii Durand & Hilgard var. sulcatum (S. Watson) Munz & Reveal in P. A. Munz, Suppl. Calif. Fl. 62. 1968.
Heermann's grooved wild buckwheat
Eriogonum sulcatum S. Watson, Proc. Amer. Acad. Arts 14: 296. 1879; E. heermannii subsp. sulcatum (S. Watson) S. Stokes
Subshrubs, spreading, densely branched, (0.5-)1-8 × 2-8 dm. Leaf blades linear-lanceolate to elliptic or spatulate, 0.4-1.2(-1.5) × 0.2-0.8 cm, thinly tomentose abaxially. Inflorescences 1-5(-8) × 3-10 cm; branches diffuse, with dichotomously arranged involucres, slender, sharply ridged and deeply grooved, minutely scabrellous, not spinose. Involucres campanulate, 0.7-1.5(-2) × 0.7-1.5(-2) mm. Flowers 1.5-2.5 mm; perianth yellowish white.
Flowering Apr-Oct. Limestone cliffs and outcrops, saltbush, blackbrush, sagebrush, and mountain mahogany communities, scrub oak and pinyon-juniper woodlands; 700-2700 m; Ariz., Calif., Nev., Utah.
Variety sulcatum is locally common and occurs typically on limestone outcrops and cliff-faces. It is found in desert ranges of southeastern Inyo and northeastern San Bernardino counties, California, in Clark and southern Lincoln and Nye counties, Nevada, and in Washington County, Utah. In Arizona the plants occur in northern Mohave County and into northwestern Coconino County. The variety would make an ideal addition to the rock garden as a subshrub if one were willing to allow sufficient time for the plants to mature. This slow-growing plant forms dense, dark green clumps of tangled inflorescence branches and is attractive even without flowers.