Crassula subulata is a succulent shrublet that grows to heights around 50 cm when the inflorescence is present. Branching at the base, the plant grows many leafy stems that are red and erect. Short recurving whitish hairs occur in two bands along the young stems below the points where the leaf-pairs join.
The leaves are opposite, smooth, 1,5 cm long and narrow, but sometimes up to 5 mm wide. Leaf-pairs are fused at the base, tapering to their upturned tips. There margins are angular, the lower leaf surface convex, the upper one flat.
Creamy white flowers grow in densely branched and flat-topped clusters at stem tips. Each flower is about 5 mm long. Flowering happens from midspring to early summer.
The species distribution is from Vanrhynsdorp in the Western Cape to Gqeberha (Port Elizabeth) in the Eastern Cape. This plant was flowering in October in the Tradouw Pass south of Barrydale.
The habitat is semi-arid, rocky slopes, the plants growing in fynbos, renosterveld and dune scrub in loamy soils. The species is not considered to be threatened in its habitat early in the twenty first century (Vlok and Schutte-Vlok, 2015; Bond and Goldblatt, 1984; iSpot; http://redlist.sanbi.org).