FILICES. (FERNS.) 659 



4. CHEILANTHES, Swartz. LIP-FERN. (PI. 16.) 



Sporangia borne on the thickened ends of free veinlets, forming small and 

 roundish distinct or nearly contiguous marginal fruit-dots, covered by a mostly 

 whitish and membranaceous, sometimes herbaceous, common indusium, formed 

 of the reflexed margin of separate lobes or of the whole pinnule. Low, mostly 

 with 2 - 3-pinnate and hairy or chaffy fronds, the sterile and fertile nearly alike, 

 the divisions not halved, the principal vein central. Some species with con- 

 tinuous indusium connect this genus very closely with the next. (Name com- 

 posed of ^fiXos, a Up, and (ivQos, flower, from the shape of the involucre.) 



1. C. vestita, Swartz. Fronds (6'- 1 5' high), lanceolate-oblong, hirsute, 

 as are the brown and shining stipes, with straightish prominently articulated rusty 

 hairs, twice pinnate ; pinnae rather distant, triangular-ovate ; pinnules oblong, 

 crowded (2" -4" long), more or less incised, the ends of the roundish or oblong lotxs 

 reflexed and forming separate herbaceous involucres, which are pushed back by the 

 ripened sporangia. (Nephrodium lanbsum, Michx. !) Clefts of rocks, Island 

 of New York ( W. W. Denslow], and New Jersey to Illinois, and southward. 



2. C. tomentbsa, Link. Fronds (12' - 20' high) lanceolate-oblong, densely 

 tomentose with slender and entangled whitish obscurely articulated hairs, thrice pin- 

 nate ; primary and secondary pinnae oblong or ovate-oblong ; pinnules distinct, 

 minute ("-1" long), roundish-obovate, sessile or adnate-decurrent, the upper 

 surface less woolly, the reflexed narrow margin forming a continuous somewhat mem- 

 branaceous involucre. Mountains of Virginia ? and Kentucky ; thence westward 

 and southward. Stipe and rhachis rather stout, brown, covered with narrow 

 chaffy scales and whitish hairs. 



3. C. lanuginbsa, Nutt. (in herb. Hook. & Sp. Fil. 1851). Stipes slen- 

 der, at first hairy, black or brown, shining ; fronds (3'- 6' high) ovate-lanceolate, 

 woolly with soft whitish distinctly articulated flattened hairs, becoming smoother 

 above, twice or thrice pinnate; pinnae (5" -6" long) ovate, the lowest distant, 

 the others contiguous ; pinnules crenately pinnatifid, or mostly divided into minute 

 and roundish densely crowded segments (i"-l" long), the herbaceous margin re- 

 curved forming an almost continuous involucre. (C. vestita, Hook. C. lanosa, Eaton, 

 Moore, excl. syn. C. gracilis, Mettenius, 1859. Myridpteris gracilis, Fe'e.) In 

 dense tufts, on dry rocks and cliffs, Wisconsin (T. J. Hale], Iowa (Vasey), Mis- 

 souri (Nuttatt, Engelmann], thence westward and southward. 



5. PELL^IA, Link. CLIFF-BRAKE. (PI. 15.) 



Sporangia in roundish' or elongated clusters on the upper part of the free 

 veins, distinct or confluent laterally so as to imitate the marginal continuous 

 line of fructification of Pteris, commonly covered by a broad membranaceous and 

 continuous (rarely interrupted) general indusium, which consists of the reflexed 

 and altered margin of the fertile pinnule or division. Small Ferns, with 1 - 

 3-pinnate fronds, the fertile ones with narrower divisions than the sterile, but 

 otherwise similar. Stipes generally dark-colored, smooth and shining. (Name 

 from TreXXo?, dusky, alluding to the stipe.) 



1. P. gracilis, Hook. Fronds smooth (3' -6' high), delicately membrana- 

 ceous and slender, of few pinnae, the lower ones once or twice pinnately parted 



