Genus of about 30 species of evergreen or semi-evergreen, epiphytic and terrestrial ferns from rainforest and more open habitats in tropical and subtropical regions worldwide. These are Ferns that are found wild in many tropical areas, including Africa, America, Malaya and the West Indies. The most popular are the varieties of N. exaltata, a plant that grows wild from Florida southward into Brazil and in Africa and eastern Asia. This Fern produces fronds, 3-5 feet in length and 2-6 inches wide. They have stiff midribs that are covered with fine brown hairs and the leaflets (pinnae), which are about half an inch wide, are set closely along each side of the midrib. There are many pretty varieties of N. exaltata. One well-known kind is N. exaltata bostoniensis, the Boston Fern, which has long, graceful, drooping fronds. The fronds of N. exaltata Piersoni, N. exaltata Piersoni improved and N. exaltata massii are bipinnate--that is, each of the little leaflets is divided into segments, giving it a feathery look. Some fronds are tripinnate, which gives them more of a fine, feathery look than the bipinnate kinds. These Ferns need a minimum temperature of 55-60 F and a fairly humid atmosphere.