Cyatheaceae

A tree fern is not a tree. Its trunk is a slender true stem sheathed in a thick mantle of adventitious roots and the persistent bases of old fronds, and it grows by adding one crown of leaves at a time from a single apical bud. There is no secondary thickening and, in the normal course, no branching. A trunk that takes decades to raise is not quickly replaced, which is the reason the family sits on CITES Appendix II — listed as Cyathea spp., a listing that covers the species now placed in Alsophila and Sphaeropteris as well.

The family is named for its scales. The stipe base carries flattened, often glossy scales rather than the hairs of Dicksoniaceae and Culcitaceae, and it is the first thing to look at in the field.