Spotted saxifrage is an attractive, tufted, cushion forming perennial. The stems creep and root at the nodes, and are freely branched, forming mats up to 15 cm wide. The leaves are rigid and closely crowded together, giving the plant a moss-like appearance. The leaves are linear-lanceolate to lanceolate, 5-15 mm long and 1.5-3 mm wide, and persist for many years. The surface of the leaves are usually glabrous while the margins are fringed with tiny hairs from their base to near the tip. The flowering stems range from 5-13 cm high with several smaller, sessile and spiny leaves on the stems from 2-6 mm long. The upper stem is generally glandular-hairy. As the cushion expands outward, the inner portion often dies, creating separate clones.
The inflorescence is a flat-topped cluster of 2-10 flowers. The 5 petals are white, 3.5-6.5 mm long and 1.5-2.5 mm wide, with distinctive red or purple dots above the middle, and yellow-orange spots near the base. The petals are oblong to oblong-oval in shape. The calyx is saucer-shaped with the lobes or sepals triangular to oval in shape, spreading, and from 1.5-2.5 mm long. The 10 stamens are shorter than the petals with the thin filaments 4-5 mm long. The ovary is only inferior at its base.
Variety austromontana - The leaves are narrowly lanceolate to linear with pointed tips. They are usually over 4 times as long as wide. Found from British Columbia south through the Cascades to Mt. Rainier and east to the Rocky Mts. where it may be found south to New Mexico. Within the Pacific Northwest, it may also be found in northeastern Oregon.
Variety vespertina - The leaves are oblong or spatulate, or occasionally 3-lobed at the tip. The leaves are not more than 4 times as long as broad. The leaf tips are blunt to obtuse. Found in the Columbia River Gorge, in the Cascades from Mt. Rainier south into Oregon, on Mt. Baldy in the Olympic Mts and at Saddle Mt. in the Coast Range of Oregon.