36 POLYPODIACEAE (FERN FAMILYJ 



2. A. Caplllus- Veneris L. Fronds (1-5 dm. high) %oith a continuous main 

 rhachis, ovate-lanceolate, often pendent, 2-3-pinnate at the base, the upper third 

 or half simply pinnate ; pinnules wedge-obovate or rhomboid, 15-32 mm. long, 

 deeply and irregularly incised ; veinlets flabellately forking from the base ; invo- 

 lucres lunulate or transversely oblong. — Moist rocky places, s. N. Y. (?) ; 

 s.e. Pa. to Ky. and Fla.; also S. Dak. and south westw. (Widely distr.) 



8. PTERIS L. Brake or Bracken 



Sporangia in a continuous slender line of fructification, occupying the entire 

 margin of the fertile frond, and covered by its reflexed narrovr edge which forms 

 a continuous membranaceous indusium, attached to an uninterrupted transverse 

 vein-like receptacle connecting the tips of the forked free veins, with or without 

 an obscure inner indusium. Fronds 1-3-pinnate or decompound. (The ancient 

 Greek name of Ferns, from TrrepSv, a wing., on account of the prevalent pinnate 

 or feathery fronds. ) 



1. P. aquilina L. (Common Brake.) Frond dull green (2-9 dm. wide), 

 ternate at the summit of an erect stout stalk (2-9 dm. high), the widely spread- 

 ing branches twice pinnate ; pinnules oblong-lanceolate ; the upper undivided ; 

 the lower more or less pinnatifid, with oblong obtuse lobes, margined all round 

 with the indusium, which is really double in this species. {Pteridium Kuhn.) 

 — ^ Thickets and hillsides, common. Aug. (Widely distr.) Var. pseudocau- 

 dIta Clute is a form with many of the pinnules, especially the terminal ones, 

 narrow, entire, and much elongated. — Mass. to N. J., south w. to Fla. and Tex. 



6. CHEILANTHES Sw. 



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 

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

 with 2-3-pinnate and hairy or chaffy, rarely smooth fronds, the sterile and 

 fertile nearly alike, the divisions with the principal vein central. Some species 

 with continuous indusium connect this genus very closely with the next. (Name 

 composed of xeiXos, margin, and di/ftos, a flower, from the marginal sori.) 



* Fronds smooth, or at most hairy. 



1. C. alabamlnsis (Buckley) Kunze. Fronds smooth, chartaceous (7-20 cm. 

 long), ovate-lanceolate, bipinnate ; pinnae numerous, oblong-lanceolate; pin- 

 nules triangular-oblong, rather acute, often auriculate or lobed ; indusium con- 

 tinuous, rather broad, pale, and of firm consistence. — On rocks, mts. of Va. to 

 Ky., south w. and westw. (Mex.) 



2. C. lanbsa (Miohx.) Watt. Fronds (1-4 dm. high) lanceolate-oblong, 

 hirsute, as are the brown and shining stipes, with straighiish prominently articu- 

 lated rusty hairs, twice pinnate ; pinnae rather distant, triangular-ovate ; pin- 

 nules oblong, crowded (4-8 mm. long), more or less incised, the ends of the 

 roundish or oblong lobes reflexed and forming separate herbaceous involucres. 

 which are pushed back by the ripened sporangia. (C vestita Sw.) — Clefts of 

 rocks, Ct. to Minn., Wyo., and south w. 



* * Fronds woolly or tomentose. 



8. C. tomentbsa Link. Fronds (1.5-5 dm. high) lanceolate-oMong, densely 

 tomentose with slender and entangled whitish obscurely articulated hairs, thrice 

 pinnate ; primary and secondary pinnae oblong or ovate-oblong ; pinnules dis- 

 tinct, minute (1-2 ram. long), roundish-obovate, sessile or .adnate-decurrent, the 

 upper surface less woolly, the reflexed narrow margin forming a continuous 

 somewhat membranaceous indusium. — Mis. of Va. and Ky. ; thence w. and 

 southw, — Stipe and rhachis rather stout, brown, covered with narrow chaffy 

 scales and whitish hairs. (Mex., W. I.) 



4. C. FeSi Moore. Stipes slender, at first hairy, black or brown, shining ; 



