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A systematic survey of lichens was performed in 2019 in four of the five territories constituting the French Scattered Islands (Europa Island, Juan de Nova, Glorioso Islands, and Tromelin) focusing on the genus Ramalina. Species were characterized using morphological (macroscopic and microscopic) features and an accurate chemical profiling method based on high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MS). Five species were found in these territories. Two of them, Ramalina dumeticola and R. ovalis, are already known. Three species are introduced here as new to science: Ramalina gloriosensis sp. nov., R. hivertiana sp. nov., and R. marteaui sp. nov. An identification key is provided for the species found in the area and morphologically closely related taxa.

The last treatment of Chenopodiaceae in Madagascar was published in 1954 and since then, the generic circumscription of Chenopodiaceae including Salicornioideae has changed drastically. The Madagascan Salicornioideae (samphires) are still insufficiently studied. Salicornia pachystachya described from Madagascar had a turbulent nomenclatural and morphological history, frequently considered as Arthrocnemum pachystachyum due to the alleged similarity of the seed characters with other Arthrocnemum species, or considered in a broader sense including the related Salicornia perrieri. However, the reproductive features of S. pachystachya confirm its placement within Salicornia, and the thick inflorescences and longer seeds distinguish it from S. perrieri, another native Madagascan species. Two other members of Salicornioideae in Madagascar are the subshrubby Salicornia mossambicensis, erroneously named S. fruticosa or Arthrocnemum natalense, and Tecticornia indica. Herein, a diagnostic key is provided for the delimitation of four samphire species in Madagascar, and the lectotypes of Salicornia pachystachya and S. perrieri are designated. Only two species, S. pachystachya and Tecticornia indica, are recorded for Europa Island, and their habitat preferences in this location are presented, as well as a discussion of the species composition and chorology of samphires in continental Africa.

Role of tree ferns in fl owering plant settlement in the tropical montane rainforests of La Réunion (Mascarene Archipelago, Indian Ocean). -The mechanisms by which species richness of tropical forests is maintained are a source of ongoing debate. Indeed, even if variety of numerous microhabitats is a possible hypothesis, results remain inconclusive. In this study natural species regeneration on the soil was compared to that on tree fern stipes, a particular microhabitat type which is a safe place for the regeneration and maintain of fl owering epiphytic plant species. Species that regenerate only underground or exclusively on tree fern stipes, or for some in these two microhabitat types, have been studied in this paper. The presence of numerous hemi-epiphytic indigenous species is highlighted and the specifi c regeneration on Cyathea spp. stipes is explained by specifi c life history traits (such as small seeds, seedling photo-sensibility, heliophilous saplings and anemochorous dissemination), which in particular give them the capability to hook on tree fern stipes and settle there. This "above ground" mode of growth should enhance the survival of heliophilous species particularly in invaded places by exotics plants. Tree ferns appear as playing an important role in the regeneration of a number of fl owering plants in Réunion tropical forests. In this 1-hectare study, 36.4 % of all regenerating fl owering plants do it exclusively on tree fern stipes. A number of these species grow seedlings up to 80 cm on fern stipes, and then put down roots. This specifi c important hemi-epiphytic plant regeneration can in part explain the important species richness of tropical forests. Therefore, in order to preserve biodiversity, it is recommended to include tree ferns in future tropical forest restoration programs.