POLYPODIACEAE. 



VOL. I. 



17. Dryopteris Robertiana (Hoffm.) C Chr. 

 Scented Oak-fern. Fig. 53. 



Polypodium Robertianum Hoffm. Deutschl. Fl. 2 : 



[add. 4]. 1795. 

 Phegopteris Robertiana A. Br. ; Aschers. Fl. Brand. 2 : 



198. 1859. 



Polypodium calcareum Sm. Fl. Brit. 1117. 1804. 

 Phegopteris calcarea Fee, Gen. Fil. 243. 1850-52. 



Rootstock slender, creeping, branched. Stipes 

 slender, straw-colored, 6'-i3' long; blades 6'-8' 

 long, s'-7' broad, copiously glandular, suberect, tri- 

 angular-ovate; basal pinnae largest, 3'~4$' long, 

 unequally deltoid-ovate, long-stalked, 2-pinnatifid; 

 second pair of pinnae distant, short-stalked or ses- 

 sile, pinnate or 2-pinnatifid, deltoid-oblong; suc- 

 ceeding pinnae sessile, narrower, mostly pinnatifid; 

 segments close, oblong to elongate-oblong, the mar- 

 gins subentire to crenate-dentate, reflexed ; sori near 

 the margin, non-indusiate, numerous. 



On shaded limestone, Labrador to Alaska. New 

 Brunswick and Iowa. Rare and local Also in Europe^ 



8. ANCHISTEA Presl, Epim. Bot. 71. 1851. 



Coarse swamp ferns with wide-creeping prostrate or underground rootstocks, the leaves 

 scattered and rigidly erect, the blades long-stalked and deeply bipinnatifid, the fertile ones 

 similar in outline to the sterile. Veins united in a single series of elongate areoles next to 

 the secondary rachis and midveins of the segments, the veinlets arising from these simple 

 or once-forked, extending to the margin, almost invariably free. Sori superficial, borne on 

 the inner side of the transverse vein forming the outer side of the areole, elongate-linear to 

 oval, covered by convex indusia attached at the outer margin. [Name from the Greek, in 

 allusion to the alliance with IVoodwardia.] 



A monotypic genus of eastern North America. 



i. Anchistea virginica (L.) Presl. 

 Virginia Chain-fern. Fig. 54. 



Blechnum virginicum L. Mant. 2: 307. 1771. 

 Woodwardia virginica J. E. Smith, Mem. Acad. 



Turin 5 : 412. 1793- 

 Anchistea virginica Presl, Epim. Bot. 71. 1851. 



Rootstock rather slender, creeping, spar- 

 ingly branched, chaffy at the apex. Stipes 

 stout, i-3 long, toward the base purphsn 

 brown and polished; blades i-2 long, 6'-o/ 

 broad, oblong-lanceolate, acute, subcoriaceous, 

 bipinnatifid; pinnae linear-lanceolate, usually 

 alternate, oblique, glabrous, sessile, acuminate, 

 3'-6' long, deeply pinnatifid into numerous and 

 usually close ovate or oblong obtuse segments, 

 their margins serrulate; sori along the sec- 

 ondary rachis elongate-linear, those of the 

 segments shorter, elliptical; indusia subentire' 

 or erose, extrorse, obscured at maturity. 



In swamps, often in deep water, Nova Scotia to Ontario and Michigan, south to Florida, 

 Louisiana and Arkansas. Ascends to 1300 ft. in Pennsylvania. Also in Bermuda. June-July. 



9. LORINSERIA Presl, Epim. Bot. 72. 1851. 



Swamp ferns of medium size, with dimorphous leaves, the sterile ones spreading, with 

 deeply pinnatifid blades, the veins copiously anastomosing; fertile leaves rigidly erect, the 

 pinnae somewhat foliaceous, but greatly reduced in width, with a single series of elongate 

 costal areoles and a few short excurrent veinlets. Sori in a single row, linear to elliptic, 

 borne as in Anchistea, superficial, sometimes appearing immersed from the pustulate mem- 

 branous leaf-tissue beneath. Indusium extrorse, firmly membranous, persistent and scarcely 

 reflexed with age. [Name in honor of Gustav Lorinser, an Austrian physician and botanist.] 



A monotypic genus of eastern North America. 



