Potentilla thurberi var. sanguinea (Rydb.) Kearney & Peebles

Potentilla sanguinea Rydberg, sp. nov
Perennial, with a thick woody tap-root and a very short caudex; stem 5-6 dm. high, light-green, appressed-pubescent, branched above, the branches erect; basal leaves pinnately 7-foliolate with closely approximate leaflets ; petioles 1-1.5 dm. long, with more spreading pubescence; leaflets 2-5 cm. long, 1-1.5 cm. wide, oblong or oblong-oblanceolate, serrate, light-green, puberulent on both sides and slightly silky on the veins beneath ; lower stem-leaves similar, but more inclined to be digitate, and with shorter petioles ; uppermost ones ternate or simple ^ stipules large, lanceolate, 1-2 cm. long ; hypanthium silky -and puberulent ; bractlets linear-lanceolate, about 5 mm. long, acute ; sepals narrowly lanceolate, acuminate, about 7 mm. long ; petals rose-purple, exceeding the sepals, obcordate ; ■stamens about 25.
Type collected about Walnut Canon, Arizona, in 1898, D. T. MacDougal (herb. N. Y. Bot. Gard. ) .