Either of two eastern North American annual plants(Pilea pumila or P. fontana) having short,drooping clusters of tiny greenish-white flowers and translucent stems and leaves.

• 北美冷水花，美豆两种北美东部一年生植物中的一种（水冷花属北美水冷花或水冷花），有短且下垂的花簇，开白色杂淡绿的小花，茎和叶透明。