Crotalaria trifoliolata (Leguminosae: Papilionoideae), a previously incompletely known Ethiopian endemic rediscovered after 120 years

摘要

The incompletely known Crotalaria trifoliolata Baker f. (Leguminosae subfam. Papilionoideae) has been rediscovered in the field. For 120 years, it has been known only from a fragmentary holotype with uncertain collecting locality. The habit and height of the plant, the pods and the seeds are here described for the first time. The new information confirms that C. trifoliolata belongs to sect. Hedriocarpae Wight & Arn. subsect. Hedriocarpae. Within that subsection it is similar to a small number of other species of Crotalaria from the Somalia-Masai floristic region (C. leucoclada Baker, C. rhynchocarpa Polhill, C. saltiana Andrews, C. thomasii Harms) in having the inside of the pod densely packed with long, white hairs. C. trifoliolata was observed at the edge of and in glades inside dry Juniperus-Olea forest, in which the canopy is dominated by J. procera Endl. and the undergrowth by Barbeya oleoides Schweinf. and other species characteristic of dry Afromontane forest and bushland. The species is found only in a limited area near the eastern Ethiopian escarpment at Sheik Hussein. It is documented with images and maps, its potential distribution is modelled and a conservation assessment is provided, suggesting that C. trifoliolata is Endangered (E).