Iberis sempervirens 'Alexander's White'
Common name: Candytuft.
Zones 3 to 9.
Plants reach 8 to 10 inches tall and 12 to 24 inches wide;
low-growing, spreading, woody-based, herbaceous perennial.
Growth rate: Moderate.
Evergreen in warmer zones.
Large clusters of pure white flowers carpet the narrow, evergreen leaves from mid to late spring. This variety is fairly tall for the species and may rebloom in the fall.