Cyatheales

Tree fern (Cyatheales) Temporal range: Late Jurassic–Recent PreꞒ Ꞓ O S D C P T J K Pg N
Dicksonia antarctica
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Subclass:	Polypodiidae
Order:	Cyatheales A.B.Frank
Families
Thyrsopteridaceae Loxsomataceae Culcitaceae Plagiogyriaceae Cibotiaceae Metaxyaceae Dicksoniaceae Cyatheaceae ?†Tempskyaceae Note: These families are alternatively treated as subfamilies of the single family Cyatheaceae [1]

The order Cyatheales, which includes most tree ferns, is a taxonomic order of the fern class, Polypodiopsida.^[2] No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicate the order is monophyletic. Some species in the Cyatheales have tree-like growth forms from a vertical rhizome, others have shorter or horizontal expanding rhizomes.

Some species have scales on the stems and leaves, while others have hairs. However, most plants in the Cyatheales are tree ferns and have trunk-like stems up to 10 metres (33 ft) tall. It is unclear how many times the tree form has evolved and been lost in the order.^[3]