Landscapes are the convergence of:

The most significant event documented on phylogenetic trees are the synapomorphies.

In many species, the younger trees have one growth form and the adult trees exhibit a different growth form. Many change from excurrent to decurrent.

The way to protect a name you have given to a special plant selection is:

One cycad was believed to be a fern for fifty years until the plant coned.

Grasses have a unique structure that often can help identify the species. It is a structure between the leaf sheath and the blade, and can be a fringe of hairs or just a membrane.  This structure is called:

When you make a cross section through a plant stem and see scattered, unorganized vascular bundles, you know you are looking at a dicot.

When a single plant has different forms of leaves, this is called:

Which set of lobing terms goes from shallowest to deepest:

The compound fruits of the Maple tree are each composed of two individual fruits called samaras. The name for the compound fruit is a samaracetum.