Cliftonia is a monotypic genus of flowering plants in the family Cyrillaceae (order Ericales), native to the southeastern United States. Its sole species, Cliftonia monophylla — commonly known as the buckwheat tree, buck-wheat tree, or black titi — is an evergreen tree typically reaching 5.5 m (18 ft), with some specimens growing to 14 m (45 ft). It has a crooked, multi-stemmed growth form with dark, shiny, thick leaves. The flowers are white to pinkish, fragrant, and borne in clusters. The distinctive fruits are five-winged drupes, yellowish and buckwheat-shaped, giving rise to the common name.
The only other genus in Cyrillaceae is Cyrilla, also monotypic. Fossil evidence shows that Cliftonia was once present in Europe during the Neogene, forming part of the Tertiary bog flora alongside Cyrilla, though today the family is restricted to the Americas.
Distribution
Cliftonia is native to the southeastern United States, in the warm temperate to subtropical regions. The Cyrillaceae family as a whole ranges from warm temperate to tropical regions of the Americas, though fossil evidence indicates Cliftonia and its relatives were also present in Europe during the Neogene period.
Ecology
Cliftonia monophylla attracts pollinators, particularly honeybees, and its foliage is browsed by deer. The genus occurs in boggy and wet woodland habitats of the southeastern coastal plain. Historically, during the Neogene, Cliftonia formed part of the shrubby bog vegetation of central Europe, alongside Cyrilla, before the family's range contracted to the Americas.
Taxonomy
Cliftonia is one of only two genera in Cyrillaceae (Ericales), the other being Cyrilla. Both are monotypic, though Cyrilla may contain additional species pending taxonomic revision. A third genus, Purdiaea, was historically placed in Cyrillaceae but is now assigned to Clethraceae. Cliftonia is an accepted genus with two name records (C. monophylla and C. nitida), the latter likely treated as a synonym.
