88 OUR NATIVE FERNS AND THEIR ALLIES. 



fronds 3' 6' long, i^' 2' broad, ovate, lanceolate, triangular- 

 ovate or deltoid, tripinnate ; primary pinnae mostly opposite, 

 the rachises nearly straight ; pinnules long-stalked ; segments 

 roundish, nearly as broad as long, terminal ones larger, entire 

 or 3-lobed ; upper surfaces green, smooth, lower densely coated 

 with pure white powder; sori brown, often descending the free 

 veins half-way to the midvein. Arizona, New Mexico. 



Var. dealbata (Pursh) Dav. Segments more numerous, 

 longer than broad, terminal ones rarely lobed. (TV*, dealbata 

 Kunze and former editions. Cheilanthes dealbata Pursh.) Up- 

 per Missouri to New Mexico and Arizona. 



13. N. Fendleri Kunze. Stipes densely tufted, dark- 

 brown, 3' 5' long ; rachis and all its branches zigzag and 

 flexuous ; fronds broadly deltoid-ovate, 3' 5' each way, quad- 

 ripinnate below, gradually simpler above; pinnae alternate; 

 ultimate pinnules oval or elliptical, simple or 3-lobed. Colo- 

 rado, New Mexico, Arizona. 



** Fronds naked below. 



14. N. tenera Gillies. Stipes tufted, brownish, smooth 

 and shining ; fronds 3' 4' long, ovate-pyramidal, bi tripinnate ; 

 pinnae mostly opposite, distant, the lower ones somewhat tri- 

 angular; ultimate pinnules ovate, often sub-cordate, obtuse, 

 smooth, and naked on both surfaces ; possibly only a form of 

 N. ntvea. Southern Utah, California. 



V. TVENITIS Swz. 



Sori linear, but the line sometimes interrupted, central or 

 sub-marginal. Veins reticulate. Name from Lat. tcenia, a 

 band. Includes five species, all tropical. 



I. T. lanceolata (L.) R. Br. Rootstock creeping; stipes i' 

 2' long ; fronds simple, 6' 13' long, ' f broad, tapering both 

 ways, the edge entire or sometimes crisped, midrib prominent ; 

 veins immersed, the exterior free and clubbed at their apices ; 

 sori ante-marginal, in a continuous line near the apex. (Lingua 

 cervina Plum., Pterts lanceolata L., Pteropsis lanceolata Desv., 

 Neurodium lanceolatum Fee.) Old Rhodes Key, Florida (Cur- 

 tiss). 



