A shrub or small tree reaching up to 9 m tall. Stems have fine ridges and are sparsely to densely covered with felt-like hairs and tiny glands. The non-glandular hairs are T-shaped or spurred. Leaves are alternate and stalked, broadly ovate to oblong-elliptic, measuring 60–150 mm long and 25–85 mm wide (sometimes as small as 15 mm long). They have an acute tip and a wedge-shaped base with margins that are nearly smooth to slightly wavy. The upper leaf surface is dark green and sparsely hairy becoming smoother over time while the underside is more densely covered with soft, felt-like hairs.

Flower heads appear at the tips of branches in flat-topped clusters and contain 10 to 25 small, sweetly scented flowers. The flower head is cup-shaped or rounded, 5–15 mm in diameter when pressed. Involucral bracts are arranged in five overlapping rows and are mostly hairless with gland dots and fringed edges. The outer bracts are small and pointed. The middle ones are obovate and may have small tails; the inner ones are longer and also pointed.

Florets range from white to creamy white or pale pinkish-mauve. The corolla is funnel-shaped, 8–10 mm long with slender lobes about 3–5 mm long. Anthers are arrowhead-shaped with small triangular tips. The style is up to 5 mm long with soft hairs near the tips and on its two branches (2.5–3 mm long). Fruits are narrow and slightly cylindrical, about 2–4 mm long with about 10 ribs. They are hairless but have small glands between the ribs. The pappus (used for seed dispersal) has two rows, with the outer row made up of narrow scales. Plants flower in autumn, winter and spring, from March to October.

Gymnanthemum coloratum looks similar to G. amygdalinum in shape and leaf texture, but G. amygdalinum has narrower, lance-shaped leaves, smaller flower heads with only five florets, rounded bracts, and slightly hairy seeds.