tree fern
noun
1- a large palm-like fern with a trunk-like stem bearing a crown of large fronds, sometimes reaching a height of 24 m and occurring chiefly in the tropics, particularly the southern hemisphere桫椤。
1.1
- Cyatheaceae and related families, class Filicopsida: seven genera, in particular Cyathea and Dicksonia.桫椤科及相关科, 真蕨纲：7属, 尤指桫椤属及蚌壳蕨属。