THE FERN BULLETIN 



VOL. VII. 



APRIL, 1899. 



NO. 2. 



LIBRARY 

 NtW YORK 

 BOTANICAL 

 HARDEN 



WYOMING PTERIDOPHYTES. 



By Elias Nelson. 



UR State cannot boast of a very long list of Pteridophytes. 



y^J They are of comparatively rare occurrence, and form an 

 inconsiderable part of our otherwise rich and varied flora. 

 However, quite a number of interesting ferns and fern allies have 

 been found within our borders. 



The climatic conditions in Wyoming are not altogether con- 

 genial to fern growth. Although many ferns are distinctly alpine 

 in habitat, yet it is in regions with much milder and more humid 

 climate, than that of Wyoming, that we find ferns growing luxu- 

 riantly. The bleak plains and arid tracts of our State are entirely 

 destitute of ferns, and it is only in the canons of the foothills and 

 in the mountains that any of these beautiful plants occur. Our 

 ferns are nearly all such as grow in more or less exposed places, 

 in dry soil or in clefts of rock. Growing under much less favora- 

 ble conditions, they have, as a rule, a much stouter habit of 

 growth than the delicate ferns so common in the Eastern States. 



Cystopteris fragilis, our commonest and most delicate fern, 

 occurs throughout the State. It is very frequent in the foothills, 

 and even ascends to comparatively high altitudes in the moun- 

 tains. Moist, shady nooks under overhanging rocks are its favor- 

 ite haunts. The two densely tufted ferns, Woodsia Oregana and 

 W. scopulina, venture out into more exposed ground. Their 

 numerous leaves, rendered rigid by the thickened rachides, stand 

 erect, and form dense masses in crevices of rocks on the .lower 

 peaks of the State. 



In the canons of the hills, Cheilanthes gracilis clings to per- 

 pendicular walls of limestone. Notholcrna Fendleri, with its 

 finely decompound leaves, white-powdery on the back, was col- 

 lected in a granite canon in Laramie county. Seemingly, it has 

 not been reported north of Colorado before. A diminutive form 

 of Pel I era atropurpurea grows on the face of shaded walls of 

 limestone in the Laramie range. It has been frequently observed 

 and seems to be worthy of at least a varietal name. It is charac- 

 terized as follows: 



