Morella pilulifera may grow as a shrub or a thin, multi-stemmed tree. It usually reaches a height of 3–4 m, but it may reach up to 12 m. Young branches are smooth, light grey and are covered with hairs. As the tree grows older the hairs fall off and the branches become rough, black and often develop a subtle reddish tinge. Branches have distinctive whitish lenticels, which are raised corky structures that allow gaseous exchange with the surrounding environment.

The leaves are simple, leathery, and can be elliptic, oval, or obovate, but the upper half is typically broader than the base. They can grow up to 110 x 50 mm, although they are usually smaller. The leaf surface is dark green to yellowish on the upper side and lighter underneath, while young leaves exhibit a shiny, bright green hue. The yellowish midrib is prominent on the underside, as are the yellowish lateral veins, which sometimes form a Y-shape before reaching the leaf margin. When viewed against strong light, particularly with a hand lens, the vein details become more visible. Each lateral vein typically ends inside a marginal tooth, adding a distinctive texture to the leaf edge. The base of the leaf is rounded, slightly narrowed, or broadly tapering, while the apex is short, pointed, rounded, or broadly tapering. The margin may be hairy and is either scalloped or jaggedly toothed away from the base. The petiole is pinkish when the leaves are still young, up to 10 mm long and hairy on new growth.

The small, unisexual flowers are inconspicuous and grow on erect spikes. Male and female flowers can appear on the same or different spikes, which reach up to 45 mm in length and are found in the leaf axils. The reddish male spikes are slightly shorter than the female ones. Each flower is subtended by a small, brown bract. There is no perianth in these wind-pollinated plants. The upright, anthers on the short filaments of the male flowers unfold through openings to release pollen. The female flowers have an independent pistil and are yellowish-green. There is only one locule and one ovule in the superior ovary. Morella pilulifera starts flowering in midwinter (July) and continues until spring (September).

The tree has small, nearly spherical, aromatic fruits, which are fleshy, single-seeded and have a hard, stony inner layer, (endocarp). They grow in short, crowded spikes and are covered with a white, waxy coating. Persistent bracts and bracteoles surround the fruits. When ripe, they turn dark brown to black with a bumpy texture. Each drupe measures up to 3 mm in diameter and typically has a waxy surface. Fruiting occurs in late spring and early summer (from October to November).