L'O POLYPODIACEAE (FERN FAMILY) 



1.11 a continuous vein-like marginal receptacle which connects the ends 

 ,,t' ili.- hidusium membranous, formed of the reflexed margin of the 



1. Pteridium aquilinum (L.) Kuhn, Decken's Reisen III. Bot. Ost-Afrika 11. 

 I .eat' often very large, the stipe and frond usually more than 1 m. in 

 length ami often '2 in.: frond broadly triangular, primary divisions stalked; 

 pinnae mo>tly pinnately lobed, with several to many rather short obtuse lobes, 

 and with a somet inics very long subentire apex. Frequent in the northern 

 half of the Tinted States and in Canada. 



7. CHEILANTHES Swz. LIP FERN 



Small ferns, with 2-4-pinnate fronds, and the under surface either smooth 



or variously covered with hair, wool, scales, or waxy powder. Ours belong to 



in which the involucres are continuous around the greater part of 



the margin of the very minute and bead-like ultimate segments, and the lower 



surface of the fronds tomentose or scaly. 



From Is toinentose beneath, but not scaly ....... 1. C. Feei. 



Fronds very scaly beneath, tomentum scanty or none . . . . 2. C. Fendleri. 



1. Cheilanthes Feei Moore, Ind. Fil. 240. 1857. Fronds 5-12 cm. long, 

 ovate-lanceolate, tripinnate or bipinnate with pinnatifid pinnules; ultimate 

 segments less than a line long; upper surface scantily tomentose, the lower 



matted with jointed woolly hairs: involucres herbaceous, very narrow. 

 C. Inuuyinosa. In dense tufts, on dry exposed rocks; Arizona to Colorado, 

 northward and eastward to the Great Lakes. 



2. Cheilanthes Fendleri Hook. Sp. Fil. 2: 103. 1858. Rootstock slender, 



lies loose and nerveless: frond 8-15 cm. long, tripinnate; ultimate pin- 

 nules rounded and entire, or obovate and 2-3-lobed, covered beneath with 

 broadly ovate acuminate scales, which are sometimes sparingly ciliate at 

 base. In crevices of rocks; Colorado to Arizona and Texas. 



8. PELLAEA Link. CLIFF BRAKE 



Rock-loving small or medium-sized ferns with pinnate or pinnatifid leaves, 

 glabrous, having neither tomentum nor scales. Sori marginal and ultimately 

 in a confluent line. Involucre membranous and continuous around the pin- 

 nules. 



:< herbaceous or subcoriaceous; the veins clearly visible. 



1'innae (, s, membranous 1. P. Breweri. 



Pinnae 2-5, subcoriaceous . . . . . . . . 2. P. occidentalis. 



Fronds coriaceous; the veins not perceptible. 



('li)M-ly tripinnate, 4-5 cm. long . . . . . . . 3. P. densa. 



Bipinnate, \^ -0 cm. long . . . . . . . . 4. P. Wrightiana. 



1. Pellaea Breweri DC. Eat. Proc. Am. Acad. 6: 555. 1866. Rootstock 



densely covered with narrow fulvous chaff: fronds membranous, 

 I ."> cm. long, simply pinnate with mostly unequally 2-lobed pinnae; the seg- 

 i the fertile frond narrower: indusium continuous, pale: veins 

 ''dly forked. From California to Utah and Colorado. 



2. Pellaea occidentalis (E. Nels.) Rydb., Underw. in Our Native Ferns 98. 

 I'.HK). HIM, i. -lock short and thick, densely covered with rusty hair-like scales: 



1 \ cm. long, dark brown, glabrous, shining, very slender: 



famdfl -1 s cm. lng. oblong, simple-pinnate; pinnae 2-5 pairs, oblong, mostly 



. dark iMvni, shining, firm and somewhat coriaceous, entire, or the 



.\iih 1 nr 2 lobes at the base: indusium broad, wholly covering the sori. 



'. atropwrpurea in part. (P. ////,// Hydb. Mem. N. Y. Bot. (lard. 1:4. 



Colorado to Montana, and west to Washing on. 



llaea densa (hn.ck.i Hook. Sp. Fil. 2: !",(), t, 125. 1858. Rootstock 

 Mender, Chaffy with blackish scales: stipes densely tufted, wiry, very slender, 





