Genus Lablab in Subfamily Papilionoideae
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!Lablab (Adans.) is a genus in tribe Phaseoleae of Fabaceae subfamily Faboideae (LPWG, 2013, 2017). A single species, Lablab purpureus, is widely accepted (POWO, 2024; WFO, 2024), with the African origin of the cultivated form well documented (Fuller & Harvey, 2006). It is best understood as a twining or scrambling herbaceous vine with trifoliolate leaves; leaflets are entire to shallowly lobed, and each leaf bears well-developed, persistent stipules. The inflorescence is an elongate raceme with flowers borne in pairs at each node. The calyx has a conspicuous, often truncate lower lip; the standard petal is large and reflexed at maturity, the keel is incurved, and the wing petals are well developed. The ovary is linear and many-ovuled, with an inferior position in flower and an obliquely terminal style. The fruit is a dehiscent, flattened pod containing one to several seeds; seeds are compressed and bear a conspicuous, curved funicle.
The range is pantropical, with wild populations in Africa and India, and widespread cultivation and naturalization in the Old World tropics (WFO, 2024). Centers of diversity correspond to these regions, and edaphic specialization is evident in both savanna/grassland and forest-edge habitats. Wild forms often occur in seasonally dry woodland and scrub (Verdcourt, 1971). Flowers are typically pollinated by bees, and long, flattened pods facilitate dispersal by wind or adhesion, although specialized mechanisms have not been fully resolved. Polyploidy is documented, but a consensus base chromosome number has not been robustly established in phylogenetic context.
Recent treatments maintain Lablab as monotypic (POWO, 2024; WFO, 2024). Historical segregates such as L. niger have been subsumed into L. purpureus or placed outside the genus; L. haussknechtii is treated as a synonym in the current consensus. Within Fabaceae, Phaseoleae relationships place Lablab in a clade with genera such as Cajanus and Rhynchosia (LPWG, 2013). The species is best known for its cultivation as a pulse (Lablab beans) and ornamental climber; it is sometimes weedy in disturbed sites, with limited invasiveness recorded in warm regions (Verdcourt, 1971). Conservation concerns for wild germplasm remain a priority to safeguard genetic diversity for future breeding and adaptation.
POWO, 2024; WFO, 2024; LPWG, 2013; LPWG, 2017; Fuller & Harvey, 2006; Verdcourt, 1971.