A semi-prostrate evergreen shrub, 4 to 8 in. high, with half woody, slightly hairy, unbranched shoots. Leaves densely arranged in whorls of threes (about seven whorls to the inch), stalkless, linear, 1⁄3 to 1⁄2 in. long, about 1⁄10 in. wide, bluntish pointed, slightly hairy about the margins, dull greyish green, rather fleshy. Flowers solitary in each leaf-axil, stalkless, 1⁄4 in. across, scarcely so long, yellow. Calyx tubular at the base, dividing at the top into four ovate lobes, two of which are conspicuously broader than the other two. Stamens yellow, eight, in two series of four, inserted near the apex of the calyx-tube; very shortly stalked.
Native of the Pyrenees. A pleasing little evergreen for the rock garden, flowering abundantly in March, and quite hardy. It is scarcely distinct specifically from T. tinctoria (Pourr.) Endl., also a native of the Pyrenees but extending into N.E. Spain and with two stations in France. Another close ally is T. dioica (Gouan) All., of wider distribution from Spain to N.W. Italy (Fl. Europ., Vol. 2, p. 260).