Spyridium riparium is an erect shrub that typically grows to a height of , its young stems densely covered with star-shaped and simple hairs. Its leaves are usually narrowly egg-shaped, long and wide on a
petiole long. The edges of the leaves are rolled under, the upper surface is more or less
glabrous and the lower surface white to pale green and densely hairy. The flowers are white or cream-coloured, and borne on the ends of branches in dense clusters wide, and in smaller groups in leaf axils. The
floral tube is about long, the
sepals about long, and both are densely covered with minute, star-shaped hairs. Flowering occurs from July to October. ==Taxonomy==