50 Polypody 



an occasional scale: scales next rootstock similar to those of 

 rootstock; those above pale brown, small, lanceolate or linear 

 or oblong, pointed, subciliate: fibrovascular bundles three to 

 four in base of petiole, the two anterior largest, uniting higher 

 up into one wedge-shaped in section or roundish and furrowed 

 on face. 



Blades ovate-oblong or narrowly oblong or rarely lanceolate- 

 deltoid, pinnatifid or divided, gradually or abruptly narrowing 

 at apex; apex crenate or serrate or at base pinnatifid or at tip 

 undulate, obtuse or acute or acuminate, often elongate: seg- 

 ments about ten to twenty-three pairs, alternate or opposite, 

 mostly separated by acute or rounded sinuses, oblong or oblong- 

 linear or oblong-lanceolate, usually obtuse, rarely acute or acumi- 

 nate, usually undulate or obscurely serrulate or crenate, rarely and 

 abnormally coarsely serrate or variously lobed or pinnatifid: a 

 few minute, pale brown or partly colorless, hyaline, linear or ob- 

 long, acuminate, ciliate or subciliate scales occasionally borne on 

 under surface along rachis and midveins of segments, upper 

 surface glabrous or an occasional scale along rachis: rachis 

 green or greenish-stramineous, convex on face and back: color 

 otherwise olive-green, the under surface pale: texture subcori- 

 aceous. 



Venation pinnate, wholly free or with occasional areolae: 

 primary branches of midveins of leaf's segments commonly 

 once-forked or at apex simple with two simple branches below, 

 the lowest branch on upper side sometimes, especially in large 

 segments, bearing a few simple or once-forked branches or in 

 apices of segments simple: apices of veinlets dilated, oval or 

 roundish, visible as straw-colored spots on face of leaf. 



Sori round, borne singly on simple superior basal branches 



