6 . University of Texas Bulletin 



Notholaena dealbata Kuntze. 



On rock bluffs along Barton Creek and Onion Creek. A small fern 

 with its leaflets whitened below. 



Southern central states. 



Pellaea atropurpurea Link. Cliff-brake. 



Rock bluffs in ravines. The leaves are twice pinnate below, once 

 above. The leathery leaflets are spore-bearing around their mar- 

 gins. The rachis is black. 



Widespread in North America. 



Pellaea flexuosa Link. 



Moist ravines. Larger than the preceding with leaves thrice pin- 

 nate. Easily recognized by its pink zigzag rachis divisions. A very 

 beautiful and singular fern. 



California to Texas and Mexico and in South America. 



Polypodium polypodioides A. S. Hitchcock (P. incanum Sw.). Poly- 

 pody. 



A small fern growing on tree trunks. The leathery evergreen 

 leaves are covered on the under surface with reddish-centered gray 

 scales. 



Southeastern states and tropical America. 



SALVINIALES 

 MARSILEACEAE Mafsilea Family 



Marsilea vestita Hook & Grev. Water Fern. 



Abundant in muddy ground along creeks. A slender stemmed 

 creeping perennial with leaves similar to a 4-leafed clover. 



Widespread in North America. 



EQUISETALES 

 EQUISETACEAE Horsetail Family 



Equisetum robustum A. Br. Horsetail, Scouring Rush. 



Along the bank of Barton Creek above the bridge, and on Walnut 

 Creek. 



A leafless rush-like plant with hollow, pointed stems. 



Widespread in North America. 



