Any of various ferns (especially those of the families Cyatheaceae and Marattiaceae) of treelike habit with a woody stem.
Many attain heights over 50 ft (15.2 m). They are natives of humid mountain forests in the tropics and subtropics and of warm temperate regions of the Southern Hemisphere. The family Marattiaceae contains six genera; one species, Angiopteris evecta , has leaves (fronds) 15 ft (4.5 m) or more in length and stems of 26 ft (60180 cm). Now-extinct members of the family date to the Carboniferous Period (354290 million years ago). Members of the family Cyatheaceae are very large, terrestrial ferns with trunklike, upright rhizomes; the nearly 1,000 species are grouped into seven genera.