FERN FAMILY 



5. DRYOPTERIS Adans. Fam. PI. 2: 20, 550. 1763. 



[AsPiDiUM Swartz, Journ. Bot. Schrad. 1800'-': 29. 1801, in part.] 



Mainly woodland ferns of upright habit, the rhizomes slender, wide-creeping, and 



nearly naked, to thick, erect, and copiously chaffy. Fronds borne singly or in a crown, 



usually stipitate, not jointed to the rhizome; fertile and sterile blades usually alike, 1-3- 



pinnate or decompound (rarely simple), glabrous or variously pubescent, only a few species 



conspicuously paleaceous ; veins free in northern species, connivent to copiously areolate in 



many tropical and subtropical species. Sori mostly roundish, dorsal, indusiate or not, the 



indusium (if present) in northern species roundish-reniform, fixed at its sinus. [Name 



Greek, meaning oak-fern.] 



A genus of several hundred species, mainly tropical. Besides the following, numerous species occur in 

 other parts of the United States. Type species, Polypodium filix-mas L. 



Indusia wanting; blades deltoid. 



Blades 2-3-pinnate below, glabrous and naked; basal pinnae long-stalked, deltoid. 1. D. dryoftcris. 



Blades pinnate-pinnatifid, hairy beneath, the midribs scaly; basal pinnae subsessile, narrowly ovate. 



2. D. phegopteris. 



Indusia present; blades lanceolate to ovate or oblong (sometimes deltoid in no. 8). 



Blades 1-2-pinnate. 



Segments entire or nearly so; veins simple or once forked. 



Blades oblong to ovate-oblong; segments densely puberulous beneath. 3. D. feci. 



Blades lanceolate or oblanceolate, distinctly narrowed at the base; segments glabrous or slightly 

 hairy beneath. 



Segments 4-5 mm. broad, the margins distinctly hyaline-papillose; veins often forked. 



4. D. orcoptcris. 



Segments about 2 mm. broad, the margins slightly hyaline; veins mostly simple. 



5. D. orcgana. 



Segments distinctly toothed; veins twice or several times forked. 



Pinnae sessile, oblong-lanceolate, the lower basal pinnule usually semicordate and overlying the 

 main rachis; veinlets spreading, all ending in salient spinelike teeth. 6. D. arguta. 



Pinnae mostly short-stalked, deltoid-lanceolate, the basal pinnules symmetrical, apart from the 

 main rachis; veinlets oblique, fewer, ending in oblique usually curved acute teeth. 



7. D. filix-mas. 



Blades essentially 3-pinnate. 



8. D. dilatata. 



1. Dryopteris dryopteris (L.) Christ. 



Oak-fern. 



Fig. 25. 



Polypodium dryopteris L. Sp. PI. 1093. 1753. 

 Phegopteris dryopteris Fee, Gen. Fil. 243. 1852. 



Dryopteris Hnnaeana C. Chr. Ind. Fil. 275. 

 Drvopteris drvoptcris Christ, Bull. Acad. 

 "Bot. 20': 151. 1909. 



1905. 

 Internat. Geogr. 



Rhizome cordlike, wide-creeping, the branches 

 bearing a few lax ovate brownish scales. Fronds 

 erect, distant, 20-60 cm. long; stipes slender, very 

 much longer than the blades, stramineous from a 

 chaffy blackish base ; blades deltoid, nearlj' equi- 

 lateral, 8-25 cm. long and broad, subternate by the 

 enlargement of the basal pinnae, these long-stalked, 

 deltoid, inequilateral, acute, 1-2-pinnate, the larger 

 pinnules pinnately lobed or divided ; upper pinnae 

 gradually simpler, sessile or adnate ; lobes oblong, 

 rounded-obtuse, entire to serrate-crenate ; sori rather 

 small, submarginal, non-indusiate; leaf tissue thin- 

 herbaceous, glabrous. 



Moist woods, thickets, and swamps, Canadian and Transition Zones; Alaska to Newfoundland, south 

 to Oregon, Arizona, New Mexico, Kansas, South Dakota, Wisconsin, and the mountains of Virginia; 

 Greenland; Eurasia. Type locality, European. 



