Abstract
Cotyledon morphology of Convolvulaceae seedlings from seaborne seeds was studied in Japan for identification at seedling stage. Mature cotyledonary leaves of seedlings found on the driftline were studied in twelve species encompassing four genera of Calystegia, Ipomoea, Operculina. Stictocardia. The characters examined include cotyledon colour, basal-apical notch distance, shape and dimensions. Characters of the cotyledonary leaves of each Convolvulaceae species examined were described and usefulness for identification at seedlings stage are confirmed. The cotyledonary leave of Calystegia soldanella which has not apical cleft is quite differ from other species, while those of Ipomoea, Operculina and Stictocardia are beloved.
