PlantaeDB Logo
Login Sign-up

Genus Dolichopentas in Family Rubiaceae

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!

Dolichopentas (Rubiaceae) is a small East‑African genus of shrubs or small trees comprising roughly four species. Its distribution centres on the montane forests and woodlands of the Eastern Arc Mountains of Tanzania and Kenya, with isolated populations in the southern Ethiopian highlands. These plants occupy moist forest understory and occasionally open woodland. The type species, Dolichopentas longiflora, was designated by Kårehed & Bremer (2021), who segregated the group from Pentas.

Morphologically the genus is defined by opposite, shortly petiolate leaves bearing interpetiolar triangular stipules. Leaves are lanceolate to elliptical, glabrous or sparsely pubescent, and bear small, acute interpetiolar stipules. Flowers are produced in terminal dichasial cymes; each flower possesses a long tubular corolla that exceeds 3 cm in length, ending in five spreading lobes. The ovary is inferior and bilocular with axile placentation, and the fruit is a dehiscent capsule bearing winged seeds adapted for wind dispersal.

The four recognized species are D. angustifolia (Udzungwa Plateau), D. robusta (Mount Kilimanjaro), D. glabra (Taita Hills) and the more widespread D. longiflora (Kenyan highlands to northern Tanzania). All occur in moist, shaded understorey at 1 500–2 600 m. The genus is confined to the Eastern Arc biodiversity hotspot, a region known for high endemism.

Intrinsic biology remains incompletely documented, but the elongated corolla suggests pollination by long‑tongued hawk moths (Sphingidae), and the winged seeds are wind‑dispersed. Chromosome counts are scarce; a base number of x = 11 has been reported (Kårehed & Bremer, 2021), though this needs confirmation.

Taxonomically, Dolichopentas was erected as a segregate of Pentas (Kårehed & Bremer, 2021) on the basis of molecular phylogenetic evidence (Thulin & Bremer, 2004). Nevertheless, global databases list the name as a synonym of Pentas (POWO, 2024; WFO, 2024), indicating ongoing debate over generic limits.

Human relevance is modest; a few species are occasionally cultivated for their ornamental long‑tubular flowers, but none are important for timber, food crops, or medicine.

Conservation assessments are incomplete, yet deforestation and habitat fragmentation threaten several narrow‑endemic populations. Habitat loss from agricultural expansion and climate change pose immediate threats, highlighting the urgency for population assessments. Future work should clarify the taxonomic status, refine species limits, and evaluate population viability to inform conservation priorities.

Pick a Species to see its components: