The fronds of tree ferns are usually very large and multiple-pinnated, but at least one type has entire (undivided) fronds. The fronds of tree ferns also exhibit circinate vernation, meaning the young fronds emerge in coils that uncurl as they grow.he order Cyatheales, which includes the tree ferns, is a taxonomic division of the fern class, Polypodiopsida.
rap noun (MUSIC) A2 [ U ] a type of popular music with a strong rhythm in which the words are spoken, not sung:
This lesson will try to answer these questions individually in order to place rap in its proper context. Rap is a vocal technique, while hip-hop is a subculture. Rap only makes up one part of hip-hop, so the two terms are not interchangeable.