Plants: pale green. Stems: pinnate, flabellate, palmate, or umbellate, rudimentary branches absent; stipe cavities absent. Leaves: margins bordered by 1 or 2 rows of long-rhomboidal cells; apex acute or acuminate; costa of lateral frond leaves ending before apex; laminal cells rhomboidal, prosenchymatous, walls thin or weakly incrassate. : Specialized asexual reproduction absent. North America, Mexico, West Indies, Central America, South America, Europe, Asia, Africa, Indian Ocean Islands, Pacific Islands, Australia.