This native woody shrub is usually 3-8' tall, but sometimes reaches 20' and achieves the stature of a small tree. It branches frequently and has a bushy appearance. The lower branches become woody and brown, while new growth is green or red. The leaves are usually opposite, although sometimes they occur in whorls of 3. They are up to 6" long and 2½" across, ovate or ovate-oblong in shape, and have slender petioles, smooth margins, and a glossy upper surface. In the typical variety of this species (described here), both the young branches and leaves are hairless, although there exists a less common variety of Buttonbush with pubescent branches and leaves. From 1-3 spherical flowerheads occur on a flowering stalk that branches when more than a single flowerhead occurs. Some of the upper branches may terminate with these flowerheads, or a flowering stalk may occur from the axils of the leaves. Each mature flowerhead is about 1–1½" across, and is covered all around with small white or cream flowers. Each flower has a narrow corolla about 1/3" long, with 4 small spreading lobes at its apex. There are 4 short stamens and a single white style that is quite long and undivided, projecting beyond the corolla. This latter characteristic provides the flowerhead with a starburst appearance. The small green calyx is tubular with 4 small teeth. It is about ¼" in length. The blooming period occurs during the summer (usually mid-summer) and lasts about 1 month. The flowers are sweetly fragrant. Each flower is replaced by a fruit that is obpyramidal (like a narrow upside-down pyramid). It contains 2 cells, each containing a single seed (occasionally, one of the cells is empty). The root system consists of a woody taproot.