花是被子植物的繁殖器官,由形态、功能各异的四个部分组成。花萼常为绿色,位于花的最外层,起保护作用;花冠是花中最惹人注目的部分,起招引昆虫的作用;雄蕊和雌蕊是生殖细胞的产生地。花部的排列对所有被子植物来说,都是按花萼、花冠、花蕊依次由外向内的。缺少某 Flower is the reproductive organs of angiosperms, by the morphological, functional four parts. Calyuse often green, located in the outermost layer of the flower, play a protective role; Corolla is the flower of the most conspicuous part, from the role of attracting insects; stamens and pistils is the birthplace of germ cells. Floral arrangement for all angiosperms, are by calyx, corolla, stamens in turn from outside to inside. Missing some