Egyptian plants included many which may not be familiar to you.
There were not very many trees in ancient Egypt, because there isn't really enough water in that area to support big trees. When the Egyptians needed wood, they had to go get it on boats from Lebanon.
There were also plants which are more familiar in the United States like wheat, barley, lentils, chickpeas and various vegetables. Egypt was famous for producing huge amounts of wheat especially; under Roman rule a lot of the wheat was sent to Rome, and then later to Constantinople.
To find out more about Egyptian plants, check out these books on Amazon.com or in your local library:
Farming & Food (The Ancient Egyptians), by Jane Shuter (1998). For kids.
Everyday Life in Ancient Egypt, by Lionel Casson (revised edition 2001). Not especially for kids, but pretty entertaining reading, and Casson knows what he's talking about.