FERN rAM!LT> 361 



6. NOTHOL^NA. Fronds once or twice pinnate, woolly, scaly or powdery be- 

 neathi fruit-dots at the ends of the veins, forming a line next the margin of 

 the divisions. 



§ 3. Spore-cases on the back along the margin of the frond, prmided leilh an inoO' 

 lucre foiined of Us refiexed and mare or less aUtred ma/rgm. 



6. ADIANTUM. Fruit-dota at the ends of the veins, borne on the inner side of a 



reflexed portion of the margin. Stalk dark and polished, sometimes ohftffy- 

 bristly. Pinnules always separate, distinctly stalked or almost sessile, but 

 never deeurrent on the rhachis. 



7. PTERIS. Spore-cases on a transverse veinlike receptacle within the margin, 



which connects the ends of the veins, and is covered by the reflexed thin 

 margin. Stalk light-colored (except iii § Doryopteris.) Pinnules or ultijaate 

 segments adnate to the rhachis, often deeurrent. 



8. PELL^A. Spore-cases in short lines on the upper part of the veins, confluent 



in a sub-marginal band of fructification, white within, more' or less covered 

 by the reflexed and commonly thin margin. Stalk dark and polished, some- 

 times chaffy. Pinnules mostly distinct, sessile or nearly so. 



§ 4. Fruit-dots oblong or linear, on transverse reticidatvng veinlets, in rows near the 

 midi'ib and parallel to itt industum of the same shape as the fruitr^t, opening 

 toward the midrib and tiMached by the outer edge to the fruitful cross-vetnlet, 



9. WOODWARDIA. Fruit-dots straight, oblong-linear, in chain-like rows, partly 



sunken in shallow cavities of the under surface of the frond. Rather large, 

 native. Veins reticulated, often very much so. 



10. DOODIA. Fruit-dots oblong, often slightly crescent-shaped, not sunken in the 



irond- Exotics ; the narrow fronds piun^tifid oy simply pinnate, 



§ 5. Fitdt-dots oblong or linear, on one or both sides of oblique veifiiets,vith involur 

 cres of like slmpe attached by One edge to the vemlet aind free aUmg the other. 



11. ASPLENICM. Fruit-dots single and placed on the upper side of the vemlets, 



rarel* double and set back to back on both sides of the same veinlet. Veins 

 mostly free. 



12. SCOLO'PENDRIUM. Fruitdots linear, elongated, double and placed face to 



face along contiguous veinlets; each pair thus seeming to be a single one 

 with an indusium opening along the middle. Frond simple, ribbonTshaped 

 -or tongue-shaped, with free forking .veins. 



13. CAMPTOSORUS. Fruit^lots various, mostly short;, those near the midrib 



double as in the last; the outer ones angled, curved or straight, simple as in 

 Asplenium. Frond simple^ tapering to a long and narrow usually rooting 

 point. Veins reticulated. 



§ 6. Fruit-dols on the bach of the veins, rarely at the ends, round or roundish, covered 

 at,leas( when young by a special indusium ofllie same general shape. Sterile 

 amd fertile fronds alike or nearly so. 



15. ASPIDIUM. Indusium flat, round or kidney-shaped, fixed at or near the cen- 



tre, opening all round the edge. Mostly rather large Ferns, from once to thrice 

 - pinnate, veins free in the native species. i 



16. CYSTOPTERIS. Indusium convex, fixed by the base partly under the fruit- 



dot, at length reflexed. Small Ferns, with delicate twice or thrice pinnate 

 fronds. Veins free. 



§ Sterilefronds broad and leafy: fertile ones with contracted and rolled; up and pod- 

 like or berry-like divisions : indusium very obscure, irregularly semicircular, 

 placed at the base of a short receptacle to which the simre-cases are attached. 



17. STRUTHIOPTERIS. Sterile fronds tall, with free veins, growing in a crown; 



fertile fronds coming up much later in an inner circle, pinnate, each pinna 

 rolled up from the edges into a somewhat cylindrical or necklace-like body, 

 COBtaiining the fruit. 



18. ONOCLEA. Fronds scattered on alotig creeping rootstock; .sterile ones with 



reticulated veins ; fertile ones twice pinnate, the divisions contracted, rolled 

 up and berry-likeir 



§ 8. Involucres star-sliaped, with broad amd ragged or else' capillary and jointed rai/s, 

 placed on the veins imder the round fruit-dots, somelime-i at first emelopmg 

 the spore-cases. 

 19 WOODSIA. Small Ferns, often growing in dense tufts: fronds once or twice- 

 pinnate : veins forked, free. 



