A naturally prostrate, carpeting species up to 2m in width but only moderately fast-growing. Leaves scale-like to 4mm long, darkish-blue to grey-green. North America from Maine to British Columbia, south to Massachusetts, on sea chffs, stony slopes and edges of boggy areas. Too large for most rock gardens but a splendid ground-cover for banks. Several cultivars with brighter blue-green foliage are available, among them the less vigorous 'Banff and the bright green 'Prince of Wales'. Ideal for the rock garden are the small, slower-growing 'Grey Pearl' up to 1m wide and 'Turquoise Spreader' to 1.2m.