''Cajanus kerstingii'' is a widely ignored
shrub
A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...
found mostly in open
savannah
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient light to rea ...
conditions across
western Africa.
It is closely related to the widely utilised ''
Cajanus cajan'', otherwise known as
pigeon pea.
''Cajanus kerstingii'' can be consumed by humans as a
cereal
A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...
,
pulse,
fibre
Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate ...
or
forage. Unfortunately, very little data exists for this plant, but "one may reasonably expect it to be of value".
Description
''Cajanus kerstingii'' is an erect shrub that grows to be .
It is a dicot in the genus ''
Cajanus'' of the subfamily
Faboideae (
).
When fully harvested, ''C. kerstingii'' produces a fruit that can be consumed by humans for various nutritional purposes.
In order to recognise the plant, one should seek green branches, or occasionally browny-purple.
The leaves are faintly striate (marked by ridges or grooves) and a glandular punctate, meaning the glands of the leaf are sunken in, noticeable when held against the light.
History, geography, ethnography
This plant grows primarily in Western African regions, namely
Burkina Faso,
Nigeria and
Ghana.
Other records show its presence in more countries, such as
Benin,
Mali,
Senegal and
Togo.
''C. kerstingii'' thrives in open savannah conditions,
lateritic
Laterite is both a soil and a rock type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by ...
hills, and can survive at altitudes of .
Several studies have shown that it is common on hilltops or hillsides, among grasses, large granite boulders, and occasionally shrubby trees.
The species was first formally described by German botanist
Hermann August Theodore Harms, in 1915 from a specimen collected by Otto Kersting in Togo in 1902.
Growing conditions
''Cajanus kerstingii'' is propagated via fruit.
''Cajanus kerstingii'' is also a perennial, non-climbing shrub, meaning it survives for more than two years.
Further advantages include its resistance to flames.
It grows best in soil that is fine and gravel-like.
Weeds, pests, diseases
There is little data describing the pests that ''Cajanus kerstingii'' is susceptible to. Across the globe, ''
Helicoverpa armigera
''Helicoverpa armigera'' is a species of Lepidoptera in the family Noctuidae. It is known as the cotton bollworm, corn earworm, Old World (African) bollworm, or scarce bordered straw (the lattermost in the UK, where it is a migrant). The larvae f ...
'' is the most commonly detrimental pest and has been known to attack species within the genus ''Cajanus''.
Specifically pertaining to ''C. cajan'', the largest impediment to growth is ''
Fusarium udum
''Fusarium'' is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the soil m ...
'', which causes
wilting.
Prevention of wider adaptation
The biggest constraint to wider use of this crop is the lack of information. Few farmers have access to useful experiences regarding ''Cajanus kerstingii''. The main constraint to the close relative ''Cajanus cajan'' is its vulnerability to a wide variety of pests and diseases.
References
{{Taxonbar, from=Q15378708
Phaseoleae
Flora of West Tropical Africa
Plants described in 1915