Ceratostema is a genus of flowering plants in the heather family Ericaceae (order Ericales), comprising about 37 accepted species of shrubs, dwarf shrubs, and lianas native to tropical South America. Described by Antoine Laurent de Jussieu in 1789 and placed in the tribe Vaccinieae within subfamily Vaccinioideae, the genus is closely related to Semiramisia. Plants reach up to 3.5 meters in height and may be terrestrial or epiphytic. They bear petiolate, alternate, coriaceous leaves and axillary, solitary inflorescences with pedicellate, inodorous flowers that are typically 4- to 6-merous. A distinctive morphological feature is pollen shed in tetrads without septa. The type species is Ceratostema peruvianum. Historical synonyms include Englerodoxa and Siphonostema.
Distribution
Ceratostema is native to tropical South America, with documented occurrence in Colombia, Ecuador, Guyana, Peru, and Venezuela. The genus inhabits montane and cloud forest habitats of the northern Andes and adjacent regions.
Taxonomy
Ceratostema was described by Antoine Laurent de Jussieu in 1789, with Ceratostema peruvianum as the type species. It belongs to the tribe Vaccinieae within the subfamily Vaccinioideae (Ericaceae) and is closely related to the genus Semiramisia. Two historical synonyms exist: Englerodoxa Hoerold and Siphonostema Griseb. A distinctive palynological feature of the genus is pollen shed in tetrads without septa. GBIF recognizes 37 accepted descendant species.
