Described from Mt Kilimanjaro by Karsch (1896) as Lentula modicicrus and recorded again by Sjostedt (1909) and as Usambilla modicicrus by Ramme (1929).
The three investigated genera--Usambilla, Rhainopomma, and Altiusambilla--proved closely related to each other, while clearly separated from South African genera such as Karruia, Lentula and Eremidium.