No you don't.

Lots of plants have leaves. A few don't, some primitive because they hadn't evolved them yet (e.g. algae) and a few because they lost them (broom, cacti). If there were no trees and nobody had ever seen a tree you could still explain leaves.

Lots of plants have wood. Things that aren't trees have wood. They're called bushes. Wood is a thing separate from trees. Not all trees have wood: bananas grow on really big herbs that people call trees because they are tree-sized, but they're herbs. Palm trees aren't really made of wood.

Yeah. But that wood and that leaves of plant don't get you a tree. You are filling in the blanks that makes something a tree with information you already know about trees.

I do not understand what you are getting at. :-(

> You need to invoke tree to define leaves and wood.

I don't think so?

All non-tree plants have leaves (almost all maybe? edit: not cacti, so not all but most). Wood can be defined biologically ("cellulose fibers embedded in a lignin matrix" or something like that)

Non tree plants still require you assume what a tree is.

Ok, but all plants have leaves so you would only have to agree on what a plant is. You are trying to make a point but it makes no sense.

EDIT: you could also have totally separate definitions on what wood and leaves are without talking about trees or plants, don't you think?

Sure. But when most people think of plants they already use a tree like thing as mental model.

People who have only seen non tree plants doesn't exist.

And nor does any non tree plant leaves help you generate a tree leaf.