Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics.

Descriptions and illustrations are presented for three new species to science, Vepris udzungwa Cheek, V. lukei Cheek (both Udzungwa Mts, Tanzania) and V. robertsoniae Cheek & Q. Luke (SE Kenyan kaya forests) in the context of a synoptic taxonomic revision, with an identification key to all the known unifoliolate taxa of Vepris in continental Africa. The remaining species are given skeletal taxonomic treatments (lacking descriptions). One widespread species in montane eastern Africa is renamed as Vepris simplex Cheek because its previous name, Vepris simplicifolia (Engl.)Mziray is predated by Vepris simplicifolia Endl. (basionym of Sarcomelicope simplicifolia (Endl.)T.G. Hartley, a widespread species of Australia, Lord Howe and Norfolk Islands, and of New Caledonia). Conservation assessments are presented for all species, or provisional conservation assessments are presented. Of the 13 taxa, 11 are considered threatened, of which six are VU, two EN and three CR, of which two are possibly extinct globally in the Uluguru Mts of Tanzania although not yet Red Listed on iucnredlist.org.

Polyceratocarpus askhambryan-iringae, an endemic tree species of Annonaceae from the Udzungwa Mountains of Tanzania, is described and illustrated. The new species is identified as a member of the genus Polyceratocarpus by the combination of staminate and bisexual flowers, axillary inflorescences, subequal outer and inner petals, and multi-seeded monocarps with pitted seeds. From Polyceratocarpus scheffleri, with which it has previously been confused, it differs in the longer pedicels, smaller and thinner petals, shorter bracts, and by generally smaller, less curved monocarps that have a clear stipe and usually have fewer seeds. Because Polyceratocarpus askhambryan-iringae has a restricted extent of occurrence, area of occupancy, and ongoing degradation of its forest habitat, we recommend classification of it as (EN)Endangered on the IUCN Red List.

East Africa is a hotspot of biodiversity with many endemic plant species. We describe three new species of the genus Uvariodendron (Annonaceae) from the coastal forests of Kenya and Tanzania. Uvariodendron mbagoi Dagallier & Couvreur, sp. nov. is endemic to Tanzania and unique within the genus by its strong bergamot scent and its tomentose fruits having regular tufts of higher hair density. Uvariodendron dzomboense Dagallier, W.R.Q. Luke & Couvreur, sp. nov. is endemic to Dzombo Hill in Kenya and is rendered distinct by its small leaves and very densely pubescent carpels. Uvariodendron schmidtii W.R.Q. Luke, Dagallier & Couvreur, sp. nov. is endemic to Shimba Hills in Kenya and differs by its small flowers and fused sepals forming a ring. Following IUCN criteria we assessed U. mbagoi and U. dzomboense as endangered (EN) while U. schmidtii is assessed as Vulnerable (VU). We also propose a new combination: Polyceratocarpus oligocarpus (Verdc.) Dagallier, comb. nov. The description of these three new species underlines the richness in endemics in East Africa and that new discoveries might arise from further botanical exploration of this region.

The Eastern Arc Mountains of Tanzania enclose high levels of plant and animal diversity with many yet to be described species. Here we describe a new species of the pan-tropical plant family Annonaceae named Uvariopsis lovettiana. It closely resembles another Eastern Arc endemic species, U. bisexualis, and its possible relationships with this species are discussed. A description with illustrations is presented as well as a suggestion for the IUCN conservation status of this new taxon.