PTER1D0PHYTA. 9 



6. PELLAEA Link. Cliff-brake. 



Rock-loving ferns of small or medium size with pinnate or pinnatifid leaves and 

 intramarginal sori borne on the ends of unconnected veins, at length confluent and 

 forming a marginal line. Indusium commonly broad and membranous, formed of 

 the reflexed margins of fertile segments which are more or less modified and mem- 

 branous. Fertile and sterile leaves similar. Stipes usually dark-colored. [Greek, 

 in allusion to the dark-colored stipes.] About 55 species, of wide distribution. 



Leaves pinnate or 2-pinnate with large pinnules. 1. P. atropurpurea. 



Leaves small, 3-pinnate, the pinnules narrow. 2. P. densa. 



1. Pellaea atropurpurea (L.) Link. (I. F. f. 64.) Rootstock short, densely 

 lothed with rusty hair-like scales. Stipes tufted, 5-15 cm. long, dark purple or 



nearly black; leaves coriaceous, lanceolate or ovate-lanceolate in outline, 1-3 dm. 

 long, 5-15 cm. wide, simply pinnate or 2-pinnate below; rachis dark-brown or 

 purple, glabrous or pubescent; pinnules and upper pinnae 2.5-5 cm - l° n g> glabrous, 

 6 mm. or less wide, short-stalked or sessile; indusium formed of the slightly 

 altered incurved margin of the pinnules; veins obscure, commonly twice forked. 

 On rocks, preferring limestone, Ont. to Br. Col., south to Conn., Ga., Ariz, and 

 N. Mex. 



2. Pellaea densa (Brack.) Hook. (I. F. f. 65.) Rootstock rather slender, 

 chaffy with blackish scales. Stipes densely tufted, wiry, slender, light brown, 7-22 

 cm. long; leaves ovate or triangular-oblong in outline, 2.5-4.5 cm. long, densely 

 3-pinnate, the segments 6-12 mm. long, linear, nearly sessile, acuminate or mucro- 

 nate, those of the fertile leaves tapering at each end, with narrowly recurved 

 margins; apices of the rare sterile leaves sharply serrate, otherwise similar to the 

 fertile ones. Mt. Albert, Gaspe, P. Q. Also from Br. Col. to Wyo. and Cal. 



7. CHEILANTHES Sw. Lip-fern. 



Mostly pubescent or tomentose rock-loving and small ferns with much divided 

 leaves, the sori terminal on the veins, ultimately more or less confluent. Indusium 

 formed of the reflexed margin of the leaf, roundish and distinct or more or less con- 

 fluent. Sporanges often much concealed in the scales or tomentum which covers 

 the segments in many species. [Greek, in allusion to the lipped indusia of some 

 species.] About 65 species, of temperate and tropical regions. 



Leaves nearly glabrous, 2-pinnate. 1. C. Alabamensis. 



Leaves hirsute and glandular, not tomentose ; indusia not continuous. 



2. C. lanosa. 

 Leaves more or less tomentose ; indusia mostly continuous. 



Leaves 5-10 cm. long ; stipes slender, at length nearly glabrous. 3. C. Feet. 



Leaves 1.5-4.5 dm. long ; stipes stout, densely brown-tomentose. 4. C. tomentosa, 



X. Cheilanthes Alabamensis (Buckl.) Kunze. (I. F. f. 66.) Rootstock 

 creeping, rather stout and short, with slender brown scales. Stipes black, 7-18 cm. 

 long, slender, wiry, villous at least towards the base with rusty wool; leaves lanceo- 

 late in outline, glabrous, 5-25 cm. long, 2-pinnate; pinnae numerous, ovate-lanceo- 

 late, acuminate, very short-stalked, the lowest usually smaller than those above; 

 pinnules oblong or triangular-oblong, mostly acute, often auriculate on the upper side 

 of the base, more or less toothed or incised; indusia pale, membranous, interrupted 

 by the incising of the pinnae. On rocks, Va. to Ala., west to Ark. and Ariz. 



2. Cheilanthes lanosa (Michx.) Watt. (I. F. f. 67.) Rootstock short, creep- 

 ing, with pale rusty-brown scales. Stipes tufted, wiry, chestnut-brown, 5-10 cm. 

 long, hirsute; leaves herbaceous, oblong -lanceolate in outline, 10-22 cm. long, 2.5-5 

 cm. wide, gradually attenuate to the apex, 2-pinnate ; pinnules somewhat distant, 

 lanceolate-deltoid, acute, deeply pinnatifid or incised, more or less covered with 

 almost bristly hairs and usually somewhat glandular, obtuse or subacute; sori 

 numerous, covered by the infolded ends of the rounded or oblong lobes. On rocks, 

 West Rock, New Haven, and southern New York to Ga., west to Mo., Ark. and 

 Tex. 



3. Cheilanthes Feei Moore. (I. F. f. 68.) Rootstock short, covered with 

 narrow brown scales lined with black. Stipes densely tufted, slender, about as long 

 as the leaves, at first covered with woolly hairs, at length nearly glabrous; leaves 



