68 THE UNIVERSITY OF OKLAHOMA 



on rocks and trees, wa'ls, and even roofs of houses. In the north- 

 ern part of its range it is usually found on rocks and about the 

 roots of trees, although in the Gulf states it may be found hiorh 

 up on the trunks and branches of trees. In appearance, it is nearly 

 an exact duplicate of the common polypodium, with the same creep- 

 ing, scaly rootstocks and leathery pinnatifid or pinnate fronds. It 

 is, however, rather smaller, and further distinguished by having 

 the stipe and under surface of the blade thickly covered with gray, 

 or brownish, peltate scales with darker centers. The upper sur- 

 face may be slightly scaly, or sniooth. The sori are of medium 

 size, and borne near the margins of the pinnules, but are seldom 

 noticeab'e, owing to the scales by which they are surrounded. 

 Usually they are so deeply sunk in the blade as to form little bosses 

 on the upper surface. 



Since this species grows in situations where m.oisture is a 

 very uncertain quantity, it has acquired the habit of curling up 

 its fronds when drought comes, and remaining in a comatose con- 

 dition until the next rain, when it again unrolls them, and the 

 vegetative functions proceed as before. During a drouth, fronds 

 have been known to uncurl in a heavy dew. Apparently dead speci- 

 mens, after weeks of desiccation, have been revived and unfolded 

 in a few hours when placed under warm and moist bell jars in 

 laboratories at the University of Oklahoma. 



Range 



This species is found as far north as Virginia, Illinois, and 

 Missouri ; but it is not common except in the gu'f states. More 

 exactly, the range is confined to the Austro-riparian (eastern area,) 

 Lower Austral, and Tropical Zones of eastern and southern United 

 States. The northern limit of this species may be said to parallel 

 the northern limits of the Austro-riparian zone, which may be char- 

 acterized as follows : 



On the north, by the south shores of the Chesapeake Bay, pass- 

 ing thence in an almost southwesterly direction along the Piedmont 

 belt to Macon, Georgia ; turning westward to Columbus, Georgia ; 

 thence to Florence, Alabama ; northward through Tennessee to 

 Henderson, Kentucky; Evansville, and Shawneetown, Il'inois; 

 across the southern tip of that state to the Mississippi river ; thence 

 south weftward to Little Rock, Arkansas ; northwestward to Ga'ena, 

 Kansas ; thence westward to Arkansas City, Kansas. The line then 

 describe^ a backward curve through Oklahoma, passing through 

 Guthrie, Oklahoma City, and Lawton, eixtendin? westward to 

 Amarillo, Texas; thence southward on meridian 101° W. to the 



