no OUR NATIVE FERNS AND THEIR ALLIES. 



7. P. reptans (Swz.) Eaton. Rootstock short, creeping; 

 stipes 3' — 10' long, clustered, gray-stamineous, slender, naked ; 

 fronds 4' — 12' long, membranous, softly hairy with branched or 

 stellate hairs, oblong-lanceolate, pinnate with nearly or quite 

 sessile, oblong, crenately pinnatifid pinnae, the apex pinnatifid, 

 often elongate and rooting; veins pinnate, simple, the basal 

 veinlets often anastomosing ; sori on the middle of the veinlets, 

 rather small, sometimes with a minute rudimentary indusium. 

 {Polypodium reptans Swz., Aspidium reptans Matt.) On cal- 

 careous rocks, on left bank of Withlacoochee River, 15 miles 

 N. E. from Brooksville, Florida (J. Donnell Smith). 



XXIII. DRYOPTERIS Adans. Shield-fern. 



Sori round, borne on the back or rarely at the apex of the 

 veins. Indusium fiat or fiattish, cordato-reniform and attached 

 by the centre or sinus. Veins nearly always free. Stipe con- 

 tinuous with the rootstock. Name from Gr. 5pv<i, oak, and 

 Tttepii, a fern. {Aspidium 'Si^t.. in part.) A cosmopolitan 

 genus containing 1 50 species. 



* Fronds thin-membranous ; veins simple or once forked. 



t Lowest pintice gradually reduced to mere lobes. 



\ Fronds in a crown from a stout, creeping rootstock. 



1. D. Montana (Vogl.) Ktze. Rootstock oblique, scaly; 

 stipes short, scaly below ; fronds \\° — 2° long, broadly lanceo- 

 late, tapering below, glandular; pinnae 2'— 3' long, deeply pin- 

 natifid, the lower slightly more distant ; sori medium size, 

 nearly marginal ; indusia more or less toothed at the margin. 

 {Polypodium montanum Vogl., P. oreopteris Ehrh.) British 

 Columbia (Macoun), Unalaska (Turner). 



2. D. Nevadensis (Eat.) Unde. Rootstock creeping, 

 densely covered with the persistent bases of former stalks ; 

 stipes short, scaly below ; fronds \\° — 3° long, lanceolate, with 

 pinnae linear-lanceolate from a broad base, and crowded seg- 

 ments slightly hairy on the veins and with minute resinous 

 particles ; sori small, nearer the margin than the vein ; indusium 

 minute, furnished with a few dark-colored marginal glands and 

 with jointed hairs on the upper surface. California. 



