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:
The hip-hop subculture that rap is a part of is one of the most influential and controversial manifestations of American culture. Rap and hip-hop represent the best of American culture in terms of creativity and resilience, but they also reflect America's history of racism and inequality.