Delosperma abbottii is mat-forming, and hangs pendent from cliff faces, with stems up to 500 mm long. The roots are fibrous. The branches are 1.8–2.0 mm in diameter, soft and brittle, at first reddish green, becoming grey-green; the internodes 12–15(–30) mm apart; surface glabrous (hairless), or with scattered hairs when young. The leaves are fleshy, flat, egg-shaped to narrowly egg-shaped, occasionally elliptic, 25–35 × 7–12 mm, spreading to slightly recurved, ending into a sharp point; surface shiny green, occasionally hairy when young; the leaf margin entire or hairy.

Flowers are solitary, produced in the leaf axils, up to 20–25 mm in diameter, on pedicels 8–10 mm long; petals magenta, mauve or yellow; the base of the flower (receptacle) is cup-shaped, 3 mm deep and 10 mm in diameter, bearing 2 outer sepals, 7–8 × 4 mm and 3 smaller, 3 × 2.5 mm. The petals in 2 series, outer linear-lanceolate, up to 15 × 1.3–1.5 mm, the inner shorter and narrower 5 × 0.2 mm; stamens in 3 series, up to 3–5 mm long. The anthers 0.7–1 mm, yellowish, ovary elevated, up to about 2 mm, 5 lobed, with 5 stigmas (female parts), 2 mm long, papillate; Capsule top-shaped, 8–10 mm in diameter, grey, old petals persistent and becoming blackish. Seed pale brown, pear shaped 0.5 × 0.4 mm in diameter, with a rough, tuberculate surface.

Flowering time is spring to autumn, with a peak in midsummer, but occasionally at other times of the year.

It is related to Delosperma stenandrum, but D. abbottii is at once distinguished by its procumbent growth habit and bearing larger, dorsiventraly flattened leaves and larger flowers of 20–25 mm in diameter, those of D. stenandrum are only 7 mm in diameter.