Camptosorus Polypodiaceae 53 



4. Athyrium angustum (Willd.) Presl. (Rhodora 19: 190-197. 1917.) 



(Asplenium Filix-femina of most authors.) Map 27. Infrequent in moist, 

 rich woods throughout the state. 

 Lab. to Man., southw. to s. N. E., the mts. of Pa., and Mo. 



4a. Athyrium angustum var. elatius (Link) Butters. Map 27a. This 

 variety is infrequent throughout the state and found in rich beech and 

 sugar maple and white and black oak woods. 



Maine to Minn., southw. to R. I., N. Y., and Mo. 



4b. Athyrium angustum var. rubellum (Gilbert) Butters. Map 27b. 

 This variety is infrequent throughout the state. The habitats of my speci- 

 mens are notable because of lack of uniformity. I have one specimen from 

 a tamarack bog and others from low, flat woods in hard, white clay soil, 

 dry black and white oak woods, bluffs of the Ohio River, and rich, moist 

 woods. 



Newf. to Que., Ont., Minn., southw. to N. Y., Pa., Ohio, and Mo. 



9. CAMPTOSORUS Link 



1. Camptosorus rhizophyllus (L.) Link. Walking Fern. Map 28. 

 Infrequent in the southern part of the state, becoming rare to absent in the 

 northern part. It grows in the shade in shallow soil on calcareous rocks on 

 rocky ledges, usually along streams. It is not usually abundant unless it is 

 found in deep shade and on rocks with considerable moisture. 



Cent. Maine to Ont. and Minn., southw. to Ga. and Kans. 



la. Camptosorus rhizophyllus f . auriculatus Clute. (Amer. Bot. 35 : 102. 

 1929.) This is a named form infrequently found with the species in this 

 state. It has the basal lobes of the leaves prolonged into slender tips. 



10. ASPLENIUM L. Spleenwort 



Frond long-attenuate at the apex. 



Stipe greenish 1. A. pinnatifidum. 



Stipe black and polished 3. A. ebenoides. 



Frond not long-attenuate at the apex. 



Frond pinnate; stipe and rachis polished, dark reddish brown. 



Pinnules sessile, oblong or oblong-linear, mostly 10-30 mm long, and distinctly 



auricled on the upper margin at the base 2. A. platyneuron. 



Pinnules subsessile, roundish-oblong or oval, 3-7 mm long, not auricled on the 



upper margin 4. A. Trichomanes. 



Frond laxly 2-3-pinnate, ultimate segments long-cuneate at the base and finely 

 toothed at the apex; stipe and rachis green 5. A. cryptolepis. 



1. Asplenium pinnatifidum Nutt. PlNNATiFlD SPLEENWORT. Map 29. 

 Rare in pockets of dry soil on cliffs in the area of sandstone outcrops. 

 Usually closely associated with Asplenium Trichomanes but less frequent. 



Se. Pa., Ohio, and Ind. to Mo., southw. to Ga. 



2. Asplenium platyneuron (L.) Oakes. Ebony SPLEEN WORT. Map 30. 

 Infrequent in the southern half of the state where it is restricted to the 

 unglaciated and sandstone areas. It probably reaches its greatest size on 

 shady slopes of some of the loess banks of the southwestern counties. In 



