Starnut Palm endocarps Astrocaryum sp. (Arecaceae): further records and a summary of those from north-western Europe

Abstract Starnut Palms belong to two genera of Arecaceae (Palmae), Astrocaryum and Hexopetion. At least 40 species are currently recognised from various tropical ecosystems of South America and in Pacific and Atlantic forests of Central America. Starnut Palm diaspores are naturally dispersed by a variety of modes, including mammals, bats, birds, fish, and freshwater currents. However, many empty endocarps inevitably float out to sea where they are widely dispersed by ocean currents and some eventually reach north-west European waters from the Caribbean region via the Gulf Stream and North Atlantic Drift. The current review collates all known published records of Astrocaryum endocarps found stranded in north-west Europe, including details of several previously unpublished records. Although the identification of starnut endocarps to species still frequently defies efforts, most of the specimens found stranded in north-west Europe are generally considered to belong to either A. standleyanum or H. mexicanum. However, considering the observed wide range of endocarp shapes and sizes, it is possible that several other Astrocaryum species may also occur in maritime areas of the North Atlantic. Morphometric studies of Astrocaryum endocarps, combined with confirmatory genetic analyses, are required in order to determine if endocarp shape is species-specific.