Kellogg’s or coast horkelia

Horkelia californica Chamisso & Schlechtendal var. sericea A. Gray, Proc. Amer. Acad. Arts 6: 529. 1865; H. cuneata subsp. sericea (A. Gray) D. D. Keck; H. kelloggii Greene; H. sericea (A. Gray) Rydberg; Potentilla kelloggii (Greene) Greene; P. lindleyi Greene var. sericea (A. Gray) J. T. Howell

Plants grayish-sericeous; eglandular hairs dense, ascending to appressed, glandular hairs obscured. Stems decumbent to ascending, 2–5(–7.5) dm. Leaflets 5–10 per side, obovate, (5–)10–25(–30) mm, not distinctly pinnately veined. Inflorescences usually ± congested; most flowers arranged in glomerules. Pedicels 1–3 mm, proximalmost to 12 mm. Flowers: hypanthium interior rim densely pilose; petals oblanceolate, 1.5–3 mm wide; filaments 1–3 × 0.5–1 mm. 2n = 28.

Flowering summer. Coastal stabilized dunes and hills, coastal scrub communities; of conservation concern; 0–200 m; Calif.

Historic populations of var. sericea occurred along the immediate coast from Alameda and Marin counties south at least to Santa Barbara County, with some littoral collections of Horkelia cuneata from Los Angeles and San Diego counties having some sericea characteristics. Reports from farther north are all based on misidentifications, for example, of H. californica in Sonoma County. The most distinctive specimens are from the northern populations in Alameda, Marin, San Francisco, and San Mateo counties, all of which apparently no longer exist. Of the recently confirmed extant populations, those that come closest to justifying continued recognition of var. sericea are in Monterey, San Luis Obispo, and Santa Cruz counties.