The cyanobacterial genus Cyanoarbor Wang (Chroococcales, Entophysalidaceae) and its occurrence in Brazil

The new cyanobacterial species Cyanoarbor violascens was found and described from subaerophytic habitats (wet lateritic soils) in the northwest region of São Paulo State, Brazil. The phenotypic generic features of the population were confirmed and the genus Cyanoarbor Wang 1989 was revised with four species recognized. Cyanoarbor rupestris Wang was first described from subaerophytic habitats in China. Cyanoarbor violascens Branco sp. nov. is here described from subaerophytic habitats (wet lateritic soils) in the northwest region of São Paulo State, Brazil, differing from other species by violet-coloured sheaths, cell sizes and ecotopic preference. Additionally, material previously identified as Chlorogloea cf. microcystoides from Nepal was recognized as belonging to Cyanoarbor and is here described as C. himalayensis M. Watanabe et Komdrek sp. nov. Chlorogloea gessneri Schiller is transferred to the genus Cyanarbor, as C. gessneri (Schiller) nov. comb. All four species can be differentiated based on a combination of morphological characters and biotopic preferences. Descriptions and an identification key of the four species of this genus are provided.