7. Saxifraga serpyllifolia Pursh, Fl. Amer. Sept. 1: 310. 1813.
Thyme-leaved saxifrage Thyme-leaved saxifrage
Saxifraga serpyllifolia var. purpurea Hultén
Plants mat-forming, not stoloniferous, rhizomatous. Leaves basal and cauline, (cauline 1-4); petiole absent; blade linear (cauline) or oblong to oblanceolate or spatulate, unlobed, 2-8.5 mm, fleshy, margins (recurved), entire, eciliate, apex obtuse, not mucronate, surfaces glabrous or glabrate. Inflorescences solitary flowers, 2-7 cm, sparsely to densely pink- to purple-tipped stipitate-glandular; bracts sessile. Flowers: sepals erect to spreading (reflexed in fruit, often purplish), broadly ovate to elliptic, margins eciliate or sometimes sparsely ciliate, surfaces glabrous; petals pale yellow, rarely purple, faded when dried, not spotted, elliptic to obovate, 4-8 mm, longer than sepals; ovary superior. 2n = 16 (Russia).
Flowering summer. Moist to dry sandy areas, cliffs, gravelly ridges, scree, tundra; 0-2200 m; N.W.T., Nunavut, Yukon; Alaska; Asia (Japan, Siberia).
The purple-flowered variant of Saxifraga serpyllifolia has been called var. purpurea.