| Cephalanthus occidentalis, Cephalanthus salicifolius|
Buttonbush cephalanthus occidentalis how to grow buttonbush
Cephalanthus is a genus of flowering plants in the Rubiaceae family. There are about six species that are commonly known as buttonbush.
They are shrubs or small trees growing to 5–15 m (16–49 ft) tall. The leaves are simple, arranged in opposite pairs or whorls of three. The flowers form a dense globular inflorescence.
Cephalanthus occidentalis is native to the eastern United States and Canada. The others occur in tropical regions of the Americas, Africa and Asia. Two species are known in cultivation.
Cephalanthus was named by Linnaeus in Species Plantarum in 1753. The generic name is derived from the Ancient Greek words κέφαλος (kephalos), meaning "head", and ἄνθος (anthos), meaning "flower".
Cephalanthus is the most basal genus in the tribe Naucleeae. Some authors have segregated it into its own monotypic tribe. The type species is Cephalanthus occidentalis.Cephalanthus angustifolius Lour. - Laos, Cambodia, Vietnam
Cephalanthus glabratus (Spreng.) K.Schum. - sarandí - Brazil, Argentina, Paraguay, Uruguay
Cephalanthus natalensis Oliv. - Tanzania, Malawi, Zambia, Lesotho, Swaziland, South Africa
Cephalanthus occidentalis L. - button-willow, common buttonbush, honey-bells - Cuba, eastern Canada, eastern, central and southern United States, California, Arizona, New Mexico
Cephalanthus salicifolius Humb. & Bonpl. - Mexican buttonbush, willowleaf buttonbush - Mexico, Honduras, extreme southern tip of Texas
Cephalanthus tetrandra (Roxb.) Ridsdale & Bakh.f. - tropical Asia from India to China and Thailand