It should be interesting how you handle telling her it is a hermaphrodite haha

'...They flower in the summer from July to August; they are also hermaphrodite which mean they have both male and female organs.'

Here is a link that might be useful: Wiki

When the tree blooms carefully look at the flower. If it has a pistil or female part and stamens or male parts in the same flower you have a perfect flower.
You could also do a search such as the one linked here. BTW its great that you are teaching your daughter about flower detail.

Here is a link that might be useful: Koelreuteria fact sheet

Oh No!

I never knew a tree could be both male and female. I'm going to have to figure out how to explain that to her, but I don't have much time. She knows I posted this question, so she'll be asking me again soon. :(

Thanks Sam! I didn't see your post when I was typing my reply. I'm going to go check out your fact sheet.

"I never knew a tree could be both male and female."

Dioecious plants (having separate male and female individuals) are the exception in the plant world! And actually, there is a broad spectrum of plant sexuality. Monoecious (having male and female flowers or sexual reproductive units - cones, etc - on a single individual) is a general term that covers lots of different arrangement.

Some plants have perfect flowers (male and female parts on the same flower), some have separate male and female flowers, some produce one sex followed by another sex later, and some have a variety of perfect and single-sex flowers. Even some dioecious plant have been know to up and change sexes (and you thought transsexualism was just a human thing).

I would throw in there somewhere that with birds, the prettier ones are usually the males. Well, that's up to you. I think the Ginkgo trees have a unique way of fertilizing each other. I don't understand it though. It's different than most trees. I hope someone else can explain it, if anyone cares. The females have stinky fruit, and most people don't plant them, in Asia where the trees are native, the people eat the female fruit. Sorry for the incomplete info.

A plant that is dioecious, (separate male and female plants), that most people know is the Holly.

Most people also assume that a female plant will have the flower and a male will not. This is not true; both sexes will have flowers as the flowers contain the sex organs. The male has stamens and the female has a pistil (known as an imperfect flower). A perfect flower has both.

Only the female will carry fruit as that is the product of the sexual reproduction in plants.

Linda