Diamond Lake horkelia

Potentilla douglasii Greene var. filicoides Crum, Leafl. W. Bot. 1: 100. 1934; Horkelia fusca subsp. filicoides (Crum) D. D. Keck

Stems (1–)1.5–3.5(–4) dm. Basal leaves green, 4–9(–12) cm; leaflets 4–8 per side, cuneate-obovate, 5–12 × 2–8 mm, ± 1/2 as wide as long, divided ± 1/2+ to midrib into 3–9 teeth or lobes, surfaces not obscured, sparsely short-villous to glabrate. Cauline leaves 2–4(–6); leaflets of proximalmost 2–5 per side. Inflorescences green, open, comprising 1/3–1/2 of stem, flowers usually arranged individually, glandular hairs sometimes red-septate; bracts acuminate-lobed, not obscuring pedicels and flowers at maturity. Flowers: epicalyx bractlets 1–2 mm; hypanthium 1–2 × 2.5–3.5 mm; petals 2–4(–5) mm; filaments 0.5–1 mm, ± as wide as long, anthers 0.5 mm; styles 1 mm. Achenes 1.2–1.5 mm.

Flowering summer. Open conifer woodlands, mainly on volcanic soil; 800–1600 m; Oreg.

Variety filicoides is known from the southern Cascade Range of southwestern Oregon, primarily in open lodgepole pine forests north and west of Crater Lake. This is the only variety in which the flowers are usually arranged individually rather than clustered into glomerules, at least in fully expanded inflorescences; some populations out of the core range have more congested inflorescences and are transitional to var. parviflora in this regard.