These cells in the plant tend to be thin walled and extremely rigid, almost woody, due to the presence of lignin within the cell wall.

Does each meristem site produce all three types of permanent tissues or are different tissues produced at the different places where meristems are located?

There are currently only around 1000 gymnosperm species in existence, meanwhile there are 250,000-350,000 species of angiosperms.

Ginkgos are really neat looking. I also found it interesting that their English name and scientific name are the same. They are very hardy trees and can grow almost anywhere in the US.

Many other plants, including the green elms on the DSU campus also have several leaflets coming off of a single stem-like structure to comprise a single leaf.