Peter Bruyns
Progress Report
The funding that the BCSS provided in 2021 and supplemented in 2022, had two parts. One part was towards the costs of a trip to Somaliland. This trip was delayed, but was finally made in October 2023. The main thrust of this trip was to visit the western part of the country, west of Borama. We also investigated the region around Sheikh (in the centre) in more detail. Around Sheikh we made the first record of the genus Schizobasis for Somalia and found a small population the rare Euphorbia cameronii. In the western region we made the first collections of Ceropegia (sect. Orbea) baldratii and Ceropegia (sect. Huernia) macrocarpa for Somalia. We also discovered several new populations of Ceropegia (sect. Echidnopsis) watsonii and of the the rare and poorly-known species C. (sect. Lalacruma) furta and C. (sect. Echidnopsis) bihendullensis.
The second part of the funding I applied for was to cover some of the costs of additional DNA-sequencing of stapeliads. This would add to our knowledge of them (i.e. add to what was written up in Bruyns & al. 2014). This additional knowledge is in preparation for two further works:
(1) A further book on the stapeliads, ‘The remaining Stapeliads: tropical Africa to SE Asia’ which would supplement my ‘Stapeliads of southern Africa and Madagascar’ of 2005.
(2) An account of the Apocynaceae for the Flora of the Arabian Peninsula & Socotra.
Although the Flora is no longer being published, I have updated an unpublished manuscript that I wrote on the Apocynaceae of Arabia in 2002. The updated account has been provisionally accepted by the journal ‘Symbolae Botanicae Upsalienses’ (Uppsala, Sweden). This involves an account of 121 species, of which 70 belong to the expanded concept of Ceropegia (which includes the stapeliads).
This programme of additional sequencing of stapeliads has been greatly assisted by the money provided by the BCSS for 10 plates of samples. We have already found that all stapeliads from Angola are related to others in southern Africa and have no connections to West Africa and also no connections to East or NE Africa. We have also found that each section (such as Huernia, Orbea) has a NE African clade that is completely separate from the southern African groupings (in sect. Huernia both an East African and a NE African/Arabian clade has been located). In some but not all cases, these clades extend into the Arabian Peninsula. Our work has revealed that all Arabian species (with the exception of Ceropegia plicatiloba) are most closely related to others in NE Africa. Several radiations from NE Africa to Socotra have been identified and only one has been found (sect. Edithcolea) that extends from NE Africa to Socotra and on into Arabia. Our work has also revealed that certain taxa previously recognized at infraspecific level need to be treated as species. A further question that requires investigation involves several species which are widely distributed (for example Ceropegia (sect. Echidnopsis) sharpei, C. (sect. Orbea) baldratii, C sprengeri and C. (sect. Huernia) lodarensis): are these monophyly entities?