Potentilla Thurberi, Scarlet Cinquefoil

Potentilla thurberi is one of only two red-flowered members of this large genus in the US. It occurs in a band from central Arizona to southwestern New Mexico, plus a few other places to the north and south.

Leaves mostly grow at the base; there are also one to three cauline leaves. Leaves are palmate, with five, occasionally seven leaflets, evenly toothed along the margins - teeth number from seven to 15. Lower leaf surfaces are pale green to whitish, while upper surfaces are darker green. Lower surfaces may be sparsely to densely covered by cottony hairs (var atrorubens), or essentially glabrous (var thurberi); both forms are as common.

Flowers, arranged in open clusters of up to 30, have five rounded, deep red, velvet-textured petals, slightly darker towards the base, and five slightly longer green sepals, sometimes flecked with red. Between the sepals are five narrower epicalyx bracts. Carpels (up to 70) and stamens are also deep red in color. Flowers are attached by hairy stalks up to 1.5 inches in length.