An evergreen prostrate shrub, the branches in the natural state often taking root and forming a thick mat as much as 10 ft wide but only a few inches high; young shoots downy. Leaves opposite, of stout, thick texture, obovate to cuneate, coarsely toothed except at the tapered base, often with three spines near the apex only; 1⁄3 to 1 in. long, 1⁄5 to 1⁄2 in. wide; green on both sides, varying from glabrous to downy beneath; stalk 1⁄12 in. or less long. Flowers blue, 1⁄8 in. wide, produced twelve to twenty together in clusters about 1 in. across at the end of short leafy shoots, each flower on a glabrous slender stalk 1⁄3 to 1⁄2 in. long. Fruit roundish oval with three conspicuous horns or excrescences on the top.
Native of western N. America from California to the State of Washington. Dried specimens are preserved at Kew that were collected in 1846 during Colonel Frémont's famous expedition to California. It is very distinct in the opposite, strongly toothed, holly-like leaves, one of its popular names being 'creeping holly'. More commonly it is known as 'squaw carpet' or 'Mahala mats'. It attains its most luxuriant growth on the eastern slope of the Oregon Cascades and in the Siskiyou Mountains, and has been described as one of the most showy and desirable of alpine shrubs. Forms with white and others with lavender-coloured flowers occur in a wild state. It should, of course, have a sunny place. Judging by the altitudes at which it grows it ought to be hardy with us; but in its early stages some protection in hard weather may be advisable.
C. pumilus Greene C. prostratus var. profugus Jeps. – This is essentially a very small-leaved extreme of C. prostratus, with leaves less than 1⁄5 in. in width. It is common at high altitudes in the Siskiyou Mountains.