|Red List Category & Criteria:
||Abuzinada, A.H. & AL-Eisawi, D.M.H. (Arabian Plants Red List Authority)
Begonia samhaensis is endemic to north-facing cliffs on the summit pinnacle and escarpments of the limestone plateau at the centre of Samha. Its area of occupancy is less than 10 km². The cliffs where it grows catch precipitation and mists (principally from the NE monsoon) and represent a unique habitat on Samha. However, it seems that this habitat is threatened by the trend of lower rainfall in the region and would be particularly vulnerable to the effects global warming (see also Ledebouria sp. nov. and Pelargonium sp. nov .). The situation is particularly critical for B. samhaensis which occupies a niche at the highest point on Samha and so, with increasing aridification, has no possibility of mitigating the effects of gradual drying by migrating upwards in altitude (c.f. the situation of Begonia socotrana on Soqotra island). A further and potentially very important problem has been a recent change in livestock management on the island. Until very recently goats and sheep were actively herded and were moved down from the limestone plateau during periods of drought. However, both the sheep (now largely feral) and the goats (actively managed only when in milk) are now left to roam freely for most of the year. Both animals are known to spend much of their time grazing on the limestone plateau and this could quickly lead to over-grazing and the eradication of plants on all but the most inaccessible ledges.