https://pgrainsforafrica.psm.msu.edu/pigeon-pea/
Pigeon pea (Cajanus cajan) is a tropical legume native to South Asia. Its high protein content and adaptability to arid environments have made it an important food crop across sub-Saharan Africa. Pigeon pea is a genetically diverse crop with several varieties that differ in time to maturity and plant architecture. A number of these varieties are perennial in nature, with a shrubby habit that helps them last several growing seasons and regrow after harvest.
Currently, concerted efforts to breed perennial pigeon pea are scarce. But the existence of perennial cultivars and the practice of ratooning pigeon pea means perennial pigeon pea could be readily implemented on smallholder farms. Perennial pigeon pea is also particularly promising in that it can be effectively integrated in cropping systems with other essential food crops such as maize and cow pea.