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:
Hip Hop Music. Hip hop music, also referred to as rap or rap music, is a style of popular music which came into existence in the United States during the mid-1970s, and became a large part of modern pop culture during the 1980s. It consists of two main components: rapping (MCing) and DJing (audio mixing and scratching).