Cerastium tomentosum 'Yo Yo' (Snow in Summer)

Drought-tolerant blooming perennial that does best in full sun and well-drained soil.  Plants reach a height of .5 feet to 1 foot with a spread of .5 feet to 1 foot, though if spent blooms are not removed, plants will self-seed and spread to form mats.  Excellent as a ground cover.  Petite white blooms appear in summer.