It is a much-branched, bushy, herbaceous, perennial plant, growing to 0.6m by 0.6m. It has reddish, brittle stems and narrow, stalked leaves 3 to 6cm long. The stems and veins of the under surface of the leaves have short, soft hairs, the upper surface of the leaves is nearly smooth, with sunken veins. The small, green stalkless flowers grow in clusters in the axils of the leaves and are in bloom all the summer. The filaments of their stamens are jointed and so elastic that if touched before the expansion of the flower, they suddenly spring from their incurved position and scatter their pollen. The whole plant can be used for cleaning glass such as windows and also copper containers. It was once used as a medicinal herb.