 It is dioecious, with the flowers (catkins) produced on single-sex trees in early spring.The male (pollen) catkins are reddish-purple and long; the female catkins are green, long at pollination, maturing long with several seed capsules(samaras) in early summer, which split open to release the numerous small seeds attached to cotton-like strands.A single tree may release 40 million seeds a season.