OCEAN CURRENT DISPERSAL OF SEVERAL TROPICAL CONVOLVULACEAE SPECIES IN KYUSHU, JAPAN

Abstract

Distribution expansion of several tropical Convolvulaceae species by ocean current dispersal were observed on the coast of Kyushu, Japan. Except Ipomoea pes-caprae which have been often reported, seedlings or adult plants of eight species from sea-borne seeds were newly found on or near the drift zone of many beaches; I. alba, I. cairica, I. fimbriosepala, I. stolonifera, Merremia peltata, Operculina turpethum and Stictocardia tiliifolia. These localities are beyond each producing area where species produce seeds and complete the life cycle.　These plants from sea-borne seeds were found on beaches where I. pes-caprae and tropical drift fruits and seeds were also found. Distribution expansion of these tropical Convolvulaceae species is a good indicator of global warming.