282 FOLYPODIACEAE 



Rachis usually conspicuously chaffy; fronds 4.5-40 cm. long. 1. D. fragrans. 

 Rachis naked or not noticeably chaffy; fronds 16-110 cm. long. 

 Pinnae triangular-oblong, or the lowest nearly triangular-ovate. 



2. D. cristata. 

 Pinnae linear-lanceolate from a somewhat broader base. 4. D. Filix-mas. 



Sori close to the margin. 3. D. marginalis. 



Indusia minute, dot-like; blades bipinnatifld to tripinnate. 



Pinnules decurrent on the narrowly-winged midribs; indusia glabrous. 



5. D. spinvlosa. 

 Larger pinnules not decurrent. 



Indusia, and frond when young, conspicuously glandular. 6. D. intermedia. 



Indusia glabrous or with only a few glands. 7. D. dilatata. 



8. ASPLENIUM L. Spleenwort. 



Blade irregularly forking. 1. A. septentrionale. 



Blade not forking. 



Blade simply pinnate. 



Stipe brown below; rachis green. 2. A. tiride. 



Stipe and rachis chestnut-brown or blackish. 



Pinnae not auricled. 3. A. Trichomanes. 



Pinnae auricled at base on the upper or both sides. 4. A. plalyneuron. 

 Blade bi- to tripinnatifld. 5. A. Adiantum-nigrum. 



9. ATHYRIUM Roth. Lady Febn. 



Pinnules commonly somewhat cuneate at base, sometimes appearing short-stalked; in- 

 dusia rarely seen, very minute and evanescent. 1. A. alpestre. 

 Pinnules more or less parallel at base down to the rachis, at least on the upper side; 

 indusia evident. 

 Indusia straight or variously curved, often shaped like a shepherd's crook. 



2. A. filix-foemina. 

 Indusia mostly curved so as to appear circular with a narrow sinus. 3. A. cyclosorum. 



10. ADIANTUM (Tourn.) L. Maiden-hair Fern, Venus'-hair Fern. 



Stipes forked into two rachlses, which bear on upper side pinnae interspersed with single 

 leaflets. 1. A. pedatum. 



Stipes not forked at apex; blades alternately bipinnate or tripinnate. 



Rachiseswavy-flexuose; leaflets very short-stalked. 2. A. modestum. 



Rachlses strongly divaricate-flexuose; leaflets mostly conspicuously stalked. 



3. A. rimicola. 



11. PTERIS L. Brake, Bracken. l. P. aguilina. 



12. CRYPTOGRAMMA R. Br. Rock-brake. 



Fronds scattered; leaf-texture very delicate; stipes brown or brownish below or through- 

 out. 1. C. Slelleri. 



Fronds tufted; leaf-texture firm. 



Stipes straw-colored. 2. C. acrosiichoides. 



Stipes chestnut-colored. 3. C. densa. 



13. PELLAEA Link. Cliff-brake. 



Segments of the blade obtuse or acute, rarely a few mucronate. 



Blades once pinnate, the pinnae mostly two-parted; stipes repeatedly marked with 



transverse crack-like depressions. 1. P. Breweri. 



Blades once or twice pinnate; stipes not marked with transverse depressions. 



Stipes and rachlses reddish brown, entirely glabrous or with only few occasional 



long flaccid jointed hairs. 2. P. glabella. 



Stipe and rachlses purplish black, rather thickly clothed with slender flaccid 

 jointed hairs. 3. P. atropurpurea. 



Segments sharp-pointed or mucronate; blades once pirmate above, bipinnate below. 



4. P. mucronata. 



14. CHEILANTHES Sw. Lip-peen. 



Blades scaly, not tomentose. 1. C. Fendleri, 



Blades tomentose beneath, with or without scales. 



Blades without scales. 2. C. Feei. 



Blades having scales. 



Ultimate segments oblong-oval ; upper surface at first scantily webby, soon glabrous. 



3. C. gracillima 

 Ultimate segments rounded, narrowed toward base; upper surface tornentose. 



4. C. Ealoni. 



15. NOTHOLAENA R. Br. 



Blades tomentose, not farinose beneath. 1. N. Parryi. 

 Blades whitish-farinose beneath, not hairy. 



Rachlses divaricate-flexuose. 2. N. Fendleri. 



Rachlses straight or nearly so, not divaricate-flexuose. 3. N. tiivea. 



16. POLYPODIUM [Tourn.] L. Polypody. l. p. hcspcrium. 



