The Surface of the Stem Photosynthesis occurs in most young stems. As time passes, woody plants develop bark, a layer of corky cells. Necessary exchange of gases takes place through the lenticels.
Lenticels are small spots or strips on the bark where the tissue is softer and looser.
Find the lenticels on the provided stems. Leaf Scars and Bundle Scars Leaf scars are the marks left by leaves that have fallen away. The shape of the leaf scar varies from species to species. Bundle scars are the marks left by the vascular bundles of the old leaves. The Internode is the region between two consecutive nodes.