Included here are the volcanic islands of St Helena and Ascension situated in the South Atlantic.
Of the endemic vascular plants so far recorded for St Helena there are about 50 species in 39 genera and 26 families. There are 10 endemic genera (marked red) but no endemic families.
On Ascension Island 10 endemics have been recorded including 4 flowering plants, Sporobolus durus, Sporobolus caespitosus (Poaceae), Oldenlandia ascensionis (Rubiaceae) and Euphorbia origanoides (Euphorbiaceae), and 6 ferns, Asplenium ascensionis (Aspleniaceae), Anogramma ascensionis, Pteris ascensionis (Adiantaceae), Dryopteris ascensionis (Dryopteridaceae), Marattia purpurascens (Marattiaceae) and Xiphopteris ascensionis (Grammitidaceae). However, 3 of these, Dryopteris ascensionis, Oldenlandia ascensionis and Sporobolus durus, have now probably become extinct.
Ashmole, P. & Ashmole, M. 2000. St Helena and Ascension Islands: a natural history. Anthony Nelson.
Balgooy, Van. M. M. J. 1969. A study of the diversity of island floras. Blumea, 17: 139-178.
Cronk, Q. C. B. 1980. Extinction and survival in the endemic vascular flora of Ascension Island. Biological Conservation, 17: 207-219.
Cronk, Q. C. B. 2000. The endemic flora of St Helena. Anthony Nelson.
Wilkinson, D. D. 2004. The parable of Green Mountain: Ascension Island, ecosystem construction and ecological fitting. Journal of Biogeography, 31: 1-4.