282 POLYFODIACEAE 



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-nias. 



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. spinulosa 

 Larger* pinnules not dectirrent. 



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



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



8. ASPLENIUM L. Spleentnort. 



Blade irregularly forking. 1. A. septentrionale. 



Blade not forking. 



Blade simply pinnate. 



Stipe browTi below; rachis green. 2. A. riride. 



Stipe and rachis chestnut-brown or blackish. 



Pinnae not auricled. 3. A. Triehomanes. 



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

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



9. ATHYRIUM Roth. Lady Fern. 



Pinnules commonly somewhat ctmeate 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 rachises, which bear on upper side pinnae interspersed with single 

 leaflets. 1. A. pedatum. 



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



Rachises wavy-flexuose; leaflets very short-stalked. 2. A. modestum. 



Rachises strongly divaricate-flexuose; leaflets mostly conspicuously stalked. 



3. A. rimicola. 



11. PTERIS L. Brake, Bracken. 1. P. aquilina. 



12. CRYPTOGRAMMA R. Br. Rock-brake. 



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

 out. 1. C. Stelleri. 



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 ])innae mostly two-parted; stipes repeatedly marked with 



transverse crack-like depres.sions. 1. P. Breweri. 



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



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



long flaccid jointed hairs. 2. P. glabella. 



Stipe and rachises purpUsh black, rather thickly clothed with slender flaccid 

 jointed hairs. 3. P. atropurpurea 



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



4. P. mucronata. 



14. CHEILANTHES Sw. Lip-fern 



Blades scaly, not toraentose. 1. C. Fendlcri. 



Blades tomentose beneath, with or without scales. 



Blades without scales. 2. C. Feci. 



Blades having scales. 



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



3. C. graciUima 

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



4. C. Eatoni 



15. NOTHOLAENA R. Br. 



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



Blades whitish-farinose beneath, not hairy. 



Rachi-ses divaricate-flexuose " 2. N. Fendlcri. 



Rachises straight or nearly so. not divaricate-flexuose. 3. N. nivea. 



16. POLYPODIUM [Tourn.] L. Polypody. l. P. hcspirium 



