I did a search to try and find out what the difference is between a male and femal american bittersweet. All I found was that you needed a male and female to make berries. Can someone tell me what the difference in flowers are?

I bought 10 bare root American bittersweet, 8 survived. One has a little light green "ball" Is that the male or female? They are still pretty small, it may be early to tell the difference. One little plant has small little round things where the branch meets the trunk of the vine. Any information is appreciated.

Thanks,

Karen