First records of Jamaican walnuts Juglans jamaicensis (Juglandaceae) from Irish and UK waters, together with observations on other walnut species reported from NW Europe

摘要

On 30 December 2015, a single specimen of Juglans was found stranded on Tramore Beach (54° 48' 25"N, 08° 30' 01"W), Rosbeg, Co Donegal, NW Ireland. A second specimen was found on Black Rock Beach, Widemouth Bay, south of Bude, north Cornwall, UK (SS19760178) c.14 March 2016. Based on morphological features, both specimens were identified as J. jamaicensis C. DC, and represent the first records of this species from Irish, UK and NW European waters. It is hypothesised that these walnuts most likely originated in the Greater Antilles where J. jamaicensis is endemic to Cuba, Hispaniola (Dominican Republic & Haiti) and Puerto Rico. At least four other species of walnut have been recorded from NW European waters: J. regia, J. nigra, J. ailanthifolia, and J. californica.