FILICES. 99 



(Allosorus pulchellus Mart, and Gale.) Western Texas and 

 New Mexico. 



ttt Fronds triquadripinnatifid; segments linear-oblong ; 

 secondary rachises margined. 



7. P. marginata Baker. Stipes tufted, 3' 9' long, casta- 

 neous, shining, slightly fibrillose at the base ; fronds 4' 6' long, 

 nearly as broad, deltoid ; the lower pinnae much the largest ; in- 

 dusium broad, continuous, the margins slightly erose ; texture 

 chartaceous. (Cheilanthcs marginata Hook.) Huachuca Mts., 

 Arizona (Lcmmoti). 



** Pinnules mucronulate or decidedly acute. 

 t Fronds narrowly linear in outline, usually bipinnate. 



8. p. ternifolia Link. Stipes tufted, nearly or quite black, 

 2 ' 6' long, fronds 4' 10' long, narrowly linear ; pinnae usually 

 9 15 pairs, all but the uppermost trifoliate; segments com- 

 monly linear, slightly mucronate, coriaceous, sessile or the 

 middle one indistinctly stalked, the edges much indexed in fer- 

 tile fronds ; indusium broad. (Pteris ternifolia Cav.) Western 

 Texas. 



9. P. brachyptera Baker. Stipes 2' 8' long, stout, pur- 

 plish-brown ; fronds 3' 8' long, narrow in outline from the as- 

 cending secondary rachises, bipinnate; pinnules crowded, 2"- 

 5" long, oblong-linear, simple or trifoliate, acute or mucronulate ; 

 margins inflexed to the midrib in fertile fronds. (P. ornithopus, 

 var. brachyptera D. C. Eaton, Platyloma helium et P. brachypte- 

 rum Moore.) California. 



ft Fronds broader, lanceolate to ovate, bi tripinnate. 



10. P. ornithopus Hook. Stipes tufted, 3' 8' long, 

 rather stout, dark-brown; fronds very rigid, 3' 12' long, 2 3' 

 broad, broadly deltoid-lanceolate, bi tripinnate ; primary pin- 

 nae spreading or obliquely ascending, linear, bearing 416 pairs 

 of trifoliate (varying from simple to 5 7 foliate) mucronulate 

 pinnules, i" 2" long; margins inflexed to midrib in fertile 

 fronds. (Allosortts mucr onatus D. C. Eaton.) California. 



11. P. Wrightiana Hook. Rootstock short, thick, densely 

 chaffy; stipes crowded, purplish-brown, 4' 6' long; fronds 

 3' 6' long, i' 3' broad, lanceolate to deltoid, trifoliate at apex, 



