Stems usually hirsute basally, rarely glabrescent, trichomes often simple, sometimes branched. Basal leaves: blade surfaces sparsely to densely pubescent, trichomes simple and stalked. Fruits (3.5-)4-5.8(-6) cm; style (0.2-)0.5-1 mm, (rarely stout). 2n = 32. Flowering Mar-Jul. Bluffs, cliffs, ledges, rocky hillsides, open woods, bottom lands, gravel bars, meadows, streamsides, upland prairies, grassy swales, hillsides, stream bottoms; 0-2500 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Labr.), N.W.T., N.S., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Conn., Idaho, Iowa, Kans., Maine, Mass., Mich., Minn., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., S.Dak., Utah, Vt., Va., W.Va., Wis., Wyo.; Asia (China, Japan, Russian Far East). Some populations in northern Indiana and northern Illinois, [e.g., Herman 8790 (Jo Davies County) and Friesner 19072 (Elkhart County), both at GH] most likely represent hybrids between the two varieties of Arabis pycnocarpa. Trichomes borne proximally on stems of these plants are a mixture of forked and simple. It is expected that hybrids can be found where the ranges of the two taxa overlap.