Potentilla rhyolitica

Ertter

J. Bot. Res. Inst. Texas 1: 50, fig. 1. 2007.

Conservation concernEndemic
Treatment appears in FNA Volume 9. Treatment on page 186. Mentioned on page 183, 184, 185.

Short hairs not well differentiated from long hairs, absent or sparse throughout. Stems 0.2–2 dm. Basal leaves ternate, rarely palmate, 2–8(–11) cm; petiole 1–6(–8) cm, long hairs abundant to dense, spreading to loosely appressed, 1–2(–3) mm, weak to ± stiff, glands ± abundant; leaflets 3(–5), central obovate to broadly elliptic, 1–3 × 0.8–1.8 cm, often distinctly petiolulate, distal 1/2–2/3 of margins evenly incised ± 1/3 to midvein, teeth 2–3(–4) per side, surfaces green to gray-green, long hairs common to dense, 1 mm, glands abundant. Inflorescences 1–10-flowered. Pedicels 0.5–1(–2) cm. Flowers: epicalyx bractlets lanceolate-elliptic, 2–4 × 1 mm; hypanthium 3–5 mm diam.; sepals 3–5 mm, apex acute; petals ± paler abaxially, bright yellow adaxially, ± obcordate, 3–7 × 2–5 mm; filaments 1.5–3 mm, anthers 0.6–1 mm; carpels 5–15, styles 2–3 mm. Achenes 1.5–2 mm, smooth to lightly rugose.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Leaves gray-green, hairs usually dense, sometimes common; styles 2–2.5 mm; achenes 1.5 mm, smooth to lightly rugose; Santa Rita and Huachuca ranges. Potentilla rhyolitica var. rhyolitica
1 Leaves green, hairs common, rarely dense; styles (2–)2.5–3 mm; achenes 2 mm, smooth; Chiricahua Range. Potentilla rhyolitica var. chiricahuensis