Perennial, closely branched, often forming subhemispherical masses 5-15 cm. diam. Stems ∞, much-branched from near base, ± 15-20 cm. tall, striate, margined. Basal lvs membr., ∞, 10-50-(75) × 15-20 mm., broad-obovate to obovate-spathulate, rounded, 3-5-nerved, gradually narrowed into broad flat petiole. Cauline lvs smaller, narrower, sub-sessile to sessile, lower ± 20 × 10 mm. Infl. of lax open to dense corymbose cymes sts almost concealing Ivs; pedicels narrowly margined. Calyx rather > 1/2 corolla-length, cut 3/4 way or nearly to base into linear-oblong obtuse lobes. Corolla white, 2-2.5 cm. diam., cut nearly to base into rounded broad-oblong lobes.