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:
Rental Assistance Program Utility Allowance Schedule. The Rental Assistance Program (RAP) is the major state-supported program for assisting very-low-income families to afford decent, safe, and sanitary housing in the private market. Participants find their own housing, including apartments, townhouses, and single-family homes.