How do tree ferns differ from woody trees?

Tree ferns differ from woody trees primarily in their internal structure and growth mechanisms. While woody trees (such as conifers and dicotyledons) develop a vascular cambium—a layer of meristematic cells responsible for secondary thickening—tree ferns do not possess this feature. Consequently, tree ferns do not produce true wood or bark in the traditional sense.12

Instead of the woody trunks found in seed plants, the trunks of tree ferns are composed of rhizomes that have been modified to grow vertically. These trunks are embedded in a dense mantle of adventitious roots, which provides the necessary structural support. Because they lack a vascular cambium, tree ferns do not undergo secondary thickening of the trunk, meaning their growth is fundamentally different from the process that creates the wood and inner bark of typical woody trees.21