Leaves mostly opposite; blades lance-linear to linear, 2-5 mm wide, margins usually strongly revolute, apices acute. 2n = 16, 32 Flowering Jul-Oct. Dry, rocky slopes and valleys, roadsides; 1200-2400 m; Ariz., Calif., Nev., N.Mex., Utah; Mexico (Chihuahua, Durango, Jalisco, San Luis Potosí, Sonora, Zacatecas).