7. Neurodium Fée, 4: 201.  1850.  
Ribbon ferns [Greek neuron, nerve, and -ium, resemblance; veinlets are embossed]  
Clifton E. Nauman
Paltonium C. Presl
Plants  epiphytic.  Stems  short-creeping, branched, 2--4 mm diam., not whitish pruinose; scales bicolored, lanceolate, somewhat clathrate, margins dentate.  Leaves  essentially monomorphic, tufted, narrowed toward apex, to 45 cm.  Petiole  articulate to stem, greenish, round in cross section, grooved at base.  Blade  linear to lanceolate-elliptic, simple, not glaucous, glabrous, margins entire.  Veins  obscure, in irregular areoles that are generally longer than wide and parallel to costa, included veinlets 1--2, simple or forked, free.  Sori  in nearly continuous, nearly marginal band (coenosorus) in distal 1/2 of blade, sometimes also with 1--3 separate oblong to circular sori proximally; indument filamentous.  Spores  minutely tuberculate.  x  = 37.
Species 1 (1 in the flora): tropical, North America, Mexico, West Indies, Central America.