A deciduous or sub-evergreen shrub to 10 ft or more high, with roundish, slender branchlets, glabrous or hairy. Leaves alternate, variable in shape from oblong or elliptical to ovate or lanceolate, 1 to 3 in. long, pointed or blunt at the apex, rounded at the base, glabrous or somewhat downy above, commonly downy beneath, especially on the veins, more rarely glabrous; margins entire or toothed towards the apex; venation pinnate or three-veined, but the latter state is commoner. Flowers also rather variable in colour from white to several shades of pale blue, produced in compound racemes each 3 to 6 in. long, a large number of which at the end of each branch form a fine panicle of blossom 9 to 12 in. long and 3 to 4 in. broad. Bot. Mag., t. 7640.
Native of California, where it was discovered by David Douglas in 1833, but not introduced until about twenty years later. It flowers in June, and is one of the most elegant wall plants of that season, producing its long, graceful panicles in great profusion. It needs the shelter of a wall. In the wild state it occurs throughout the length of California and shows considerable variation; the characters of the many varieties that have been distinguished are included in the above generalised description; they probably represent no more than states of one polymorphic species. C. nevadensis Kell. is now included in C. integerrimus as one of these varieties, viz. var. californicus (Kell.) Benson. It is commonest in the Sierra Nevada and has three-veined leaves; flowers commonly white.