Study on the cold hardiness physiology of winter buds of Brasenia schreberi Gmel. Temperature characteristics of winter Buds‘ dormancy in Platanus acerifolia MORPHOLOGICAL STUDIES ON THE DEVELOPMENT AND COLD RESISTANCE OF THE WINTER BUDS OF ZIZANIA CADUCIFLORA HAND.-MAZZ. Influence of water turbidity on germination of Potamogeton crispus and growth of germinated seedling