PlantaeDB Logo
Login Sign-up

Genus Icacina in Family Icacinaceae

In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.

Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.

Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).

Do you wish to read more about plant taxonomy? Click here!

Genus Description

Suggest a correction!

The family is Icacinaceae in the order Gentianales (Kårehed, 2001). About five species are currently accepted, distributed across West and Central Africa (POWO, 2024; WFO, 2024). The type species is Icacina senegalensis A.Juss., which serves as the nominal taxon for the genus.

Morphologically, Icacina consists of evergreen shrubs or small trees up to about six metres. Leaves are opposite, simple, entire, leathery and bear minute, caducous stipules. Inflorescences are short axillary racemes or fascicles. Flowers are small, five‑merous, with free sepals and free, greenish‑white petals; the five stamens are opposite the petals. The ovary is superior, syncarpous, usually with two to three ovules per locule and basal placentation. The fruit is a fleshy drupe containing a single seed (Kårehed, 2001).

Diversity is concentrated in the Gulf of Guinea and Congo Basin, with several taxa showing strong local endemism. Typical habitats range from primary evergreen forest to secondary woodland and often occur below 800 m elevation. The pattern of disjunct West–Central distribution mirrors that of many other African Icacinaceae, reflecting historical rainforest refugia (POWO, 2024; WFO, 2024).

Pollination is little documented but likely involves small insects; drupes are probably dispersed by birds or mammals. Life‑history studies are sparse, though individuals appear shade‑tolerant and reportedly flower during the dry season. Chromosome numbers have been reported for a few species: 2n = 28 (x = 14) for Icacina senegalensis and similar base numbers throughout the family (Kårehed, 2001; Soltis et al., 2020).

No subgeneric classification is currently recognized (POWO, 2024); molecular phylogenies consistently place Icacina within the African clade of Icacinaceae, closely related to Cassinopsis and Mappianthus (Kårehed, 2001; Soltis et al., 2020). Recent treatments retain the genus as distinct, although Haller (2012) suggested synonymising Icacina mannii with Icacina gabonensis (Haller, 2012), a view not adopted by the major checklists (POWO, 2024; WFO, 2024). Alternative treatments occasionally merge the genus with Mappianthus, but most modern sources keep it separate.

Humans make little direct use of Icacina. A few species bear edible fruits, but none is cultivated for horticulture or timber, and none is recorded as invasive.

Conservation assessments are lacking for most taxa, and the genus is likely threatened by ongoing deforestation and habitat fragmentation. Focused field surveys and genetic studies are needed to clarify the conservation status of the remaining species.

Pick a Species to see its components: