, a shrub, usually blooms in April and May, but the flowering period can be extended through summer and into the fall during favourable conditions. Leaves are borne in opposite pairs, at intervals all along the stems; they are relatively thick, have a slightly rough surface, and edges which may be smooth or lined by fine teeth. Leaves grow on very short stalks.
The flowerheads form in compact clusters from the upper leaf nodes, with adjacent flowers overlapping. The pointed, green, equal-length phyllaries have a dense covering of stalked glands. Heads have five (occasionally six) florets, white in color, opening to five small lobes, and a branched, protruding style. The outside of the floret tube is covered by short, stiff hairs. The tube is relatively narrow, the length about three times the width.