Pellcea. 79 



X. PELL^A, Link. Cliff-brake. 

 Sori intramarginal, terminal on the veins, at first dot-like or 

 decurrent on the veins, at length confluent laterally, forming a 

 marginal line. Indusium commonly broad and membranous, 

 formed of the reflexed margin of the fertile segment. 



1 I. CHEILOPLECTON, Fee, Baker. Texture herbaceous 

 or sub-coriaceous, veins clearly visible, indusium broad, in most of 

 the species rolled over the soriis till maturity. 



1. P. Breweri,* D. C. Eaton. Stipes densely tufted, covered 

 with narrow crisped fulvous chaff; fronds 2' — 6' high, simply pin- 

 nate, the pinnae short-stalked, 6 — 8 pairs, membranous, mostly 

 2-parted, the upper segment larger ; segments obtuse, in the fertile 

 frond narrower ; indusium continuous, pale ; veins repeatedly 

 forked. Col. to Cal. and southward. IV. 



2. P. gracilis, Hook. Stipes scattered, slender, 2' — 3' long, 

 stramineous or pale brown ; fronds 2' — \' long, i' — 2' broad, 

 ovate, bi — tripinnatifid ; pinnae lanceolate-deltoid, cut to the 

 rachis intb a few broad blunt slightly lobed pinnules ; texture 

 thinly herbaceous, flaccid ; indusium broad, continuous, membra- 

 nous; veins of the fertile fronds mostly only once forked. Lab- 

 rador to Pa., III., Col. and northward. II. 



2 2. ALLOSORUS, Baker. Texture coriaceous, the veins not 

 perceptible ; indusium broad, conspicuous. 



* Pinnules or segments obtuse or barely acute. 

 \ Fronds pinnate or bipinnate, never tripinnate. 



3. P. atropurpurea, Link. Stipes tufted, 2' — 6' long, dark- 

 purple; fronds 4' — 12' long, 2'— 6' broad, lanceolate or ovate- 

 lanceolate, simply pinnate or bipinnate below ; pinnules and upper 

 pinnffi i' — 2' long, %' broad or less, nearly sessile, smooth ; in- 

 dusium formed of the slightly altered incurved edge of the pin- 

 nules. Ariz., N. Mex., Tex. to Vt. and northward. III. 



4. P. aspera,* Baker. Stipes slender, 2' — 3' long, black with 

 scurfy pubescence ; fronds 4' — 6' long, oblong-lanceolate, bipin- 

 nate ; pinnae and pinnules deltoid-lanceolate or oblong, pinnules 

 next to main rachis often lobed ; all of them rough on both sur- 

 faces with short harsh hairs. {Cheilanthes aspera,Hoo\i.) Western 

 Tex. and N. Mex. V. 



W Fronds bi—quadripinnate, ultimate segments oval or cordate. 



5. P. andromedsefolia. Fee. Stipes scattered, erect, pale 

 brown, 2' — 12' long; fronds 6' — 12' long, 3' — 6' broad, ovate, bi— 

 quadripinnate usually tripinnate ; pinnas rather distant, spreading ; 



