A prostrate shrub formed of wiry, densely interwoven branchlets. Leaves tightly appressed, barely 2mm long on the smallest forms and up to 5mm on more vigorous clones, elliptic, coriaceous and concave. Flowers narrowly bell-shaped, 4-6mm long with green or red-tinged calyces and white to creamy-white corollas. Northern Japan to Alaska on volcanic slopes and rocks. C.I. var. crista-pilosa is a recently introduced plant from the Queen Charlotte Islands, British Columbia, and from one location in Washington State. It is one of the larger growing forms making mats to 8cm in height with branchlets 2-3mm in diameter. Flowers cream, freely borne, 6mm across. C.I. var. globularis is very compact with more rounded flowers than the type. Japan.
C.I. var. gracilis is probably the smallest form of C. lycopodioides attaining less than 2mm in height and spreading slowly to form a congested mat of dark green branchlets between 1 and 2mm thick. Japan. C.l. 'Rigida' syn. C. rigida is a much more open plant growing to 10cm in height with branchlets up to 4mm in diameter and leaves 5mm long. Rarely cultivated now as flowers are not so freely produced as with the more compact forms. Reputed to have been introduced from Japan, but plants with identical characteristics have been raised from seed collected in Alaska. C.l. 'Beatrice Lilley' is small and dense growing with freely produced flowers.
C.mertensiana (Bong.) D. Don. Widely clump-forming, 15cm high with branches spreading but erect at the tips. Leaves appressed, 3.5mm long, 1.5-3mm wide, dark green. Flowers on 1cm long pedicels from leaf axils with red or green calyces and white or white flushed pink corollas up to 6mm in diameter. Western North America from Sierra Nevada and Rocky Mountains at alpine levels. Cm. var. californica is thicker stemmed being mostly encountered in cultivation in the forms 'Blush' and 'Red Lakes'. Both of these have red pedicels and calyces and a distinct pink tinge to the corollas which is more evident when the plants are grown in cooler climates. California in the northern Sierra Nevada at 3000-3500m. Cm. var. ciliolata has sparse hairs on the leaf margins but is otherwise indistinguishable from the type. Also from the northern Sierra Nevada. Cm. var. gracilis is common in cultivation being both free-flowering and graceful in habit with slender stems 2mm thick, leaves 2-3mm long and minutely ciliate. Rocky Mountains of Oregon, Idaho and Montana.