FOLYPODIACEAE (^FEliN FAMILY) Sl 



fronds (8-1' cm. high) ovate-lanceolate, woolly with soft whitish distinctly 

 articulated flattened hairs, becoming smootlier above, twice or tlirice pinnate; 

 pinnae (8-12 niin, long) ovate, the lowest distant, tlie others contiguous; pin- 

 nules cremitely pinnatifld, or mostly divided into minute and roundisli densely 

 crowded segments (1-2 mm. long), the herbaceous margin recurved and forming 

 an almost continuous indusium. (0. lanuginosa Nutt.) —In dense tufts, on 

 dry rocks and cliffs, 111. to Minn., thence w. and south w. 



7. PELLAEA Link. Cliff Brake 



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 7reXX6s, duski/, alluding to the stipe.) 



1. P. atropurpurea (L.) Link, Smooth, except some bristly-chaffy hairs on 

 the midribs and especially on the dark purple and polished stalk and rhachis, 

 1-0 dm. high; fronds coriaceous, pale, once or below twice pinnate; the divi- 

 sions broadly linear or oblong, or the sterile sometimes oval, chiefly entire, some- 

 what heart-shaped or else truncate at the stalked base ; veins about twice forked. 

 — Dry calcareous rocks, " N. H.^' and Vt. to R. I., Ga., and westw. ; not common. 

 July. Var. cristata Trel. is a form with dichotomously forked pinnae, somewhat 

 crowded toward the summit of the frond. — Eureka, Mo. {G. Pauls). 



8. CRYPTOGRAMMA R. Br. Rock Brake 



,\uit dots roundish or elongated and extending far down on the free forking 

 veins. Margins of the fertile segments herbaceous or more or less scaiions, at 

 first reflexed and meeting at themidrib, at length openiiig out flat and exposing 

 the confluent sporangia. — Low ferns, with smooth 2-3-pinnate tufted fronds, 

 the fertile ones taller than the sterile, and with narrower divisions, (Name 

 from KpvTTTds, hidden, and ypajufxTj, a line, alluding to the lines of sporangia 

 at first concealed by the reflexed margin.) 



* jRevolnte margins of the fertile frond hearing a distinct scarious indusial 



border ; ultimate segments of the sterile fronds lance-linear, acute. 



1. C. densa (Brack.) Diels. Fronds not very dissimilar, 8-20 cm. high ; 

 stipes purplish brown ; segments of the sterile fronds lance-linear, very acute, 

 incisely serrate. {Pellaea ^oo\.) — Calcareous or serpentine walls of ravines, 

 etc., Mt. Albert, Ga.sp6 Co., Que. ; Grey Co., Out. ; and in the far west. 



* * Revolute margins of the fertile frond scarcely modified; ultimate segments 



of the sterile fronds broader. 



2. C. acrostichoides R. Br. Fronds markedly dissimilar ; segments of the 

 fertile linear (6-10 nun. long), of the sterile ovate-oblong, o?)«?^se, serrulate ; 

 stipes straw-colored, scaly especially toward the base. — Crevices of rocks, 

 Arctic Am. to L. Huron, L. Superior, Col., and Cal. 



8. C. Stelleri (Gmel.) Prantl. Fronds markedly dissimilar; segments of 

 the fertile linear-oblong to lance-linear; those of the sterile ovate to obovate- 

 ftabeUiform, crenulate,' decurrent at their cuneate bases. (Pellaea gracilis 

 H(iok.) —Shaded chiefly calcareous rocks. Que. and N. B. to Vt., Ct., n. Pa., 111., 

 and northwestw. ; local. (Asia.) 



9 WOODWARDIA Sm. Chain Ferx 



Fruit dots oblongr or linear, arranged in one or more chain-like rows on trans- 

 verse anastomosing veinlets parallel and near to the midrib. Indusi'j.m fixed by 



