688 Slosson: New ferns from tropical America 



not likely to be mistaken for any other. Marked by its bright 

 shining green color, rounded, undulate or not more than sublobate 

 margins, and few flabellately forked veins tapering toward the 

 apex. From Trichomanes sphenoides Kunze, which also has fla- 

 bellately forked veins tapering toward the apex, it may be easily 

 distinguished by the greater distance between the tips of the true 

 veins, varying from .5 to 2 or 2.5 mm., and by the very thick 

 walls of the cells of the laminae. 



Polystichum machaerophyllum Slosson sp. no v. 



Rhizome erect, its scales light brown, 2.5-6 mm. long, ovate 

 to oblong, fimbriate or subfimbriate; scales of lower part of the 

 stipes similar, passing into minute scales scattered over both sur- 

 faces of the frond, which are elongate-caudate, entire or slightly 

 toothed, from a short more or less fimbriate-ciliate base; fronds 

 up to 51 cm. long, up to 7.1 cm. broad; stipes 2.5-20.5 cm. long, 

 brownish-stramineous or greenish, channeled on the face, rounded 

 at the back, the upper part channeled also or flattened on the 

 sides; rachis similar to upper part of the stipe; laminae brownish 

 olive, lanceolate or lance-linear, slightly tapering toward base, 

 pinnate, the apex in young fronds often deltoid-acuminate, in 

 mature fronds of two kinds, the first subcaudate, elongate-linear 

 or lanceolate, subentire or undulate or serrate-lobate, often pro- 

 liferous at tip, the second flagelliform and proliferous at tip, naked 

 or with a few small scattered pinnae, both kinds sometimes on 

 the same frond, the second terminating the first; pinnae mostly 

 alternate, 8-27 to a side, usually approximate or distant, the lower 

 short-stalked, the upper sessile or subsessile or adnate, often 

 passing into short variously shaped often obovate segments, 

 principal pinnae broadly cuneate-hastate, above the auricles 

 deltoid to linear, the basal margins entire, the outer margin sub- 

 entire or undulate or with one or more minute occasionally spines- 

 cent teeth or in large fronds irregularly crenately lobed, the lobes 

 sometimes mucronate, basal auricles and apex of pinnae spinescent; 

 texture coriaceous-chartaceous; venation pinnate, obscure, veins 

 very oblique, about 1-4 times forked, the basal auricles with 

 distinct midveins; sori usually about midway between the midvein 

 and the margin of the frond, or nearer the midvein, rarely a few 

 submarginal; indusia more or less erose or with a few cilia; spo- 

 rangia glabrous; spores cristate. 



Type in the Underwood Herbarium at the New York Botanical 



Garden, collected at Arroyo del Medio, above the falls, Sierra 



