Small trees or shrubs, sometimes epiphytic or scandent. Leaves petiolate, 1.8-13.2 cm long; 7-21-veined. Inflorescences terminal, less often axillary, cymose, or flowers solitary, dichasial (if cymose); bracts and bracteoles scale-like. Flowers pedicellate, with 4-merous calyx and 6-merous corolla, actinomorphic; calyx divided to base, coriaceous, campanulate, lobes triangular, ovate, to oblong-elliptic, usually not winged or keeled (winged in C. sipapoanum), apex acute to acuminate; corolla bud apex tapering; corolla fused for 2/3-4/5 of total length, thin, salver-shaped, funnel-shaped or tubular, 25-70 mm long; androecium actinomorphic; stamens inserted in tube near base of corolla, of equal length, base of filaments without specialized structures, anthers linear, with sterile appendage (barely there in C. rotundifolium); pollen in monads; pistil with disk, stigma bilamellate. Fruit a capsule, with deciduous (initially persistent) calyx and deciduous corolla, fruit walls becoming twisted and broken into 4 valves at dehiscence, with prominently visible and loose vascular veins in center and on inner fruit wall surface; seeds flattened, lenticular, rimmed, testa pattern papillose to rounded and smooth (C. psychotrioides), alveolate.
Guayana Highlands present, Guianas present, Guyana present, Neotropics present, Southern America: Venezuela (Venezuela present), Suriname present
5 species in the Neotropics, restricted to the Guayana Highlands of Venezuela and Guyana, 850-2400 m alt., with one disjunct collection from the Tafelberg in Suriname, 400 m alt.; 4 species in the Guianas.