Antidesma pulvinatum is a tree that grows between 2 to 12 meters tall and has irregularly corrugated bark. The leaves are simple and alternate, with blades that are ovate to broadly elliptic or occasionally elliptic-obovate. The leaves measure 7.5–15(–20) cm long and 4–8(–10.5) cm wide. The base of the leaf is truncate to cordate, often asymmetrical. The upper surfaces are glabrous, while the lower surfaces feature conspicuous tufts of hairs in the angles formed by the lateral veins and midrib, especially near the base of the leaf, and sometimes puberulent along the veins. The blades are thin and chartaceous, with entire margins. The petioles are straight, 12–30 mm long, and tomentose. Stipules are linear-lanceolate, about 4–5 mm long, and quickly deciduous. The flowers are unisexual. Staminate flowers are found in densely tomentose panicles measuring 5–6 cm long, sessile, with bracts about 0.5 mm long. The calyx of the staminate flowers is 4-lobed and approximately 0.5 mm long, densely tomentose. Staminate flowers have 4 exserted stamens with filaments about 2 mm long. Pistillate flowers are found in panicles 4–9 cm long, with pedicels (1.5–)2–5 mm long and bracts approximately 0.3–0.5 mm long. The calyx of pistillate flowers is 4–6(–8)-lobed, approximately 0.8–1 mm long, and tomentose, though less densely so than in staminate flowers. Petals are vestigial. The pistillate flowers lack stamens and have a superior tomentose ovary with a terminal style. The fruit is reddish to dark purple, fleshy, and compressed, measuring 4–7 mm long and 3–4.5 mm thick, containing 1(2) seeds. It occurs in dry to mesic forests between (30–)300–600(–1,220) meters.