Ledermanniella yiben sp. nov. (Podostemaceae), Critically Endangered at the proposed Yiben Reservoir, Sierra Leone

Abstract

In the course of a botanical baseline survey for the proposed Yiben Hydroelectric Dam on the Seli River, upriver of the Bumbuna Dam, Sierra Leone, in April 2016, the second and third authors encountered a species of Podostemaceae, van der Burgt 1992. The plants were scattered densely along the gneissic rock bed of the river, then at its seasonal lowest level, largely dry, and with only a small channel of moving water, it being the end of the dry season. The plants were 20 – 50 cm diameter, spaced at distances of up to 50 cm apart from each other, with bare gneissic base rock in between, and appear restricted to the vicinity of a single set of rapids.