Morphology and systematics of the Scytopetalaceae

The present study is based on a re‐investigation of the vegetative and reproductive structures of the West African family Scytopetalaceae. Special emphasis is paid to inflorescence morphology and seed anatomy. The inflorescences of all genera of Scytopetalaceae can be interpreted as derived from panicles through reductions and structural changes. Thyrsoids prevail, but panicles, botryoids and racemes occur as well. Within the family cauliflory appears as the derived condition. Seed coat structure is extremely simplified and very stable in the Scytopetalaceae. The horny endosperm contains amyloid as the main storage compound. The presence of two obviously different forms of ruminate endosperm indicates that rumination arose twice within the family. The neotropical genus Asteranthos (Lecythidaceae) agrees in almost all relevant characters with the Scytopetalaceae. Therefore the proposed inclusion of Asteranthos in the latter family is fully confirmed. Scytopetalaceae, Lecythidaceae, Foetidiaceae and Napoleonaeaceae apparently form a natural alliance. Two new subfamilies (Scytopetaloideae, comprising Scytopetalum, Oubanguia , and Asteranthos; Rhaptopetaloideae comprising Rhaptopetalum, Pierrina and Brazzeia ) are proposed and fully described.