Buttonbush

Description

Cephalanthus is a genus of flowering plants in the Rubiaceae family. There are about six species that are commonly known as buttonbush. C. occidentalis is a deciduous shrub or small tree that averages 1–3 m (3.3–9.8 ft) in height, but can reach 6 m (20 ft). The leaves are opposite or in whorls of three, elliptic to ovate, 7–18 cm (2.8–7.1 in) long and 4–10 cm (1.6–3.9 in) broad, with a smooth edge and a short petiole. The flowers are arranged in a dense spherical inflorescence 2–3.5 cm (0.79–1.38 in) in diameter on a short peduncle. Each flower has a fused white to pale yellow four-lobed corolla forming a long slender tube connecting to the sepals. The stigma protrudes slightly from the corolla. The fruit is a spherical cluster of achenes (nutlets).