PlantaeDB Logo
Login Sign-up

Genus Pterolobium in Subfamily Caesalpinioideae

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!

Pterolobium (R.Br. ex Wight & Arn.) is a genus of the legume family (Fabaceae) that contains about 30 accepted species (POWO, 2024; WFO, 2024). The genus occurs across tropical Africa, Madagascar, the Indian subcontinent and southeastern Asia, inhabiting savanna woodlands, dry forest margins and rocky slopes from low elevations to roughly 1 500 m. Its type species is P. camara (L.) Benth.

The plants are woody shrubs or small trees, sometimes twining, and bear bipinnate leaves with numerous small leaflets; stipules are often reduced to sharp prickles. Inflorescences are axillary or terminal racemes or panicles bearing the classic papilionaceous flower: a broad standard petal, two lateral wings and a central keel. The ovary is superior and usually contains a single ovule; after fertilisation it develops into a flattened legume bearing a prominent wing along one edge, a structure that facilitates wind‑assisted dispersal.

Species richness is centred in eastern Africa and Madagascar, where several narrow endemics such as P. madagascariense are restricted to montane forest fragments, and in the Indian subcontinent where a broader suite of taxa occupies drier woodland and thorn scrub. The genus shows a typical African‑Asian disjunction, with few taxa extending into Malesia.

Pollination is primarily by bees that visit the nectar‑rich flowers, and the winged pods are wind‑dispersed. No well‑documented base chromosome number is currently available for the group.

Molecular work places Pterolobium in subfamily Caesalpinioideae, tribe Pterolobieae, within the so‑called mimosoid clade (LPWG, 2017; Bruneau et al., 2008). Phylogenetic analyses (Lewis et al., 2005) recover two informal lineages distinguished by fruit shape, but a formal subgeneric classification has not been widely adopted. Recent regional floras retain the broad circumscription of the genus, though several local varieties have been merged under P. stellatum, underscoring a degree of taxonomic fluidity.

Several species, notably P. camara, are cultivated as ornamental hedges for their spiny habit and attractive foliage, while local peoples use the wood for tool handles. None of the taxa constitute major timber resources, and only occasional weedy behaviour has been noted in disturbed sites.

Habitat loss through agricultural conversion and overgrazing threatens several narrow endemics, and targeted field surveys combined with genetic analyses are required to evaluate extinction risk and inform conservation planning.

Pick a Species to see its components: