Cuviera

Cuviera is a genus of flowering plants in the family Rubiaceae native to tropical Africa. It was originally described by Augustin Pyramus de Candolle in 1807 and is named after the French naturalist Georges Cuvier. The species form a homogeneous group that is well characterized by their striped petals, many-flowered inflorescences and (usually) ant holes in the twigs. The bracts are recaulescent, which means that the first node of the inflorescence is bare and the lowest bracts are inserted at the second node. (Wikipedia, retrieved 10-19-2020)

Verstraete, et al (2013) - Small trees or shrubs, 1–14 m high, evergreen, with regular horizontal branching (Roux's architectural model); vegetative parts glabrous or rarely puberulent; twigs usually with swollen and hollow internodes, inhabited by ants (solid in C. trilocularis and occasionally in C. acutiflora); young plants and coppicing shoots frequently armed with paired supra-axillary spines that sometimes persist on the trunk.

Cuviera has ten species in the Guineo–Congolian rainforest zone (including Bioko Island). The centre of diversity is in Lower Guinea; only two species occur in Upper Guinea (C. acutiflora and C. macroura) and only one extends into Congolia (C. angolensis). Most species are relatively light demanding, favouring secondary or riverine forest, although some can be found in the understory as well. They are frequently gregarious, especially C. physinodes that may form dense thickets locally.

Several aspects of the biology of Cuviera would be interesting to study in the field, in particular the association with ants, which presumably play a role in protecting the plant (although in our experience they are not aggressive to humans). Whether different Cuviera spp. have different associated ants is not known.

References

• Verstraete, B., O. Lachenaud, E. Smets, S. Dessein and B. Sonké. Taxonomy and phylogenetics of Cuviera (Rubiaceae–Vanguerieae) and reinstatement of Globulostylis with the description of three new species. Botanical Journal of the Linnean Society. 173(3):407–441 (doi:10.1111/boj.12062).