A monograph of Cyrtostachys (Arecaceae)

Abstract

Cyrtostachys Blume (Areceae: Arecaceae) is treated in this study as a genus of tree palms with a disjunct distribution pattern across Malesia and consisting of seven species. Three species are newly recognised (C. bakeri Heatubun, C. barbata Heatubun and C. excelsa Heatubun). Five previously accepted species (C. brassii Burret, C. kisu Becc., C. microcarpa Burret, C. peekeliana Becc. and C. phanerolepis Burret) are reduced to synonymy with C. loriae Becc. and one species (C. compsoclada Burret) is removed to Heterospathe as Heterospathe compsoclada (Burret) Heatubun, while C. ledermanniana Becc. is considered as a doubtful taxon. A determination key is presented and detailed descriptions provided for all taxa. A phylogenetic analysis of all species in the genus was performed based on morphological data. Despite the poorly resolved tree topologies, Cyrtostachys is resolved as monophyletic, with C. glauca H. E. Moore as sister to all other species, and the west Malesian species C. renda Blume probably representing a dispersal from within a Papuasian clade into the Sunda shelf. Natural history observations, including uses and conservation status are also presented in this monograph. © 2009 The Board of Trustees of the Royal Botanic Gardens, Kew.