Tetramolopium rockii, a member of the aster family, is a glandular, hairy, prostrate shrub which forms complexly branching mats 5 to 10 cm (2 to 4 in) tall and 8 to 40 cm (3 to 16 in) in diameter. Leaves of variety calcisabulorum are 2 to 3 cm (0.8 to 1.2 in) long and 5 to 7 mm (0.2 to 0.3 in) wide, have slightly inrolled edges, and are whitish due to the long silky hairs on their surfaces. Variety rockii has smaller, less hairy, flat, yellowish-green leaves, 1.5 to 2.1 cm (0.6 to 0.8 in) long and about 4 to 6 mm (0.2 in) wide. The leaves of both varieties are spatula-shaped with glands and smooth margins. Flower heads, arranged singly at the ends of flowering stalks 4 to 12 cm (1.6 to 4.7 in) long, have a hemispherical involucre (set of bracts beneath the florets). Approximately 60 to 100 white ray florets, 3 to 4.5 mm (0.1 to 0.2 in) long and 0.5 to 1 mm (0.02 to 0.04 in) wide, surround 30 to 55 functionally male, yellow, funnel-shaped disk florets. Fruits are achenes, 2 to 2.5 mm (0.08 to 0.1 in) long and about 0.7 to 0.9 mm (0.03 in) wide when fertile, and are topped with White bristles 2.5 to 4 mm (0.1 to 0.2 in) long. This species differs from others of the genus by its growth bait, its hairy and glandular surfaces, its spatulate leaf shape, and its yellow disk florets