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, also spelled hip hop or hiphop is a rhythm focused popular music style, originating from New York in the 70s. The term rap is sometimes used synonymously with hip-hop music. Hip-hop arose when DJs began isolating the percussion break from funk or disco songs for audiences to dance to.