112 Proceedings of the Biological Society of Washington. 



Type in the U. S. National Herbarium, No. 827,224, collected in the 

 mountains 12 to 14 leagues south of Saltillo, State of Coahuila, Mexico, 

 March 22 to 30, 1880, by Edward Palmer (No. 1390). A second specimen 

 of the same collection is mounted on sheet No. 41,934. 



Determined by Eaton 1 as Cheilanthes gracillima, a species described 

 from the Cascade Mountains, Oregon, and ranging from Vancouver Island 

 to western Montana, southward in the mountains to Nevada and the 

 Yosemite region, California. Notwithstanding its much greater size, it 

 resembles C. gracillima considerably in outline and subdivision of the 

 lamina; but in minute characters that species is very different, for example, 

 in the presence of minute, deciduous, stellate scales (rather than hairs) upon 

 the upper surface of the segments, and in the scaly vestiture of the rachises, 

 the scales being much narrower and copiously long-ciliate (rather than 

 erose-denticulate) . The relationship of C. castanea is apparently with 

 C. Eatoni, from which species it differs sufficiently in its fewer and several 

 times larger segments, these glabrate above and separate, not closely 

 enveloped and held together by a mass of entangled hairs arising from both 

 surfaces, as in C. Eatoni. The scales of the rachises are quite different in 

 character also. 



Pringle's 11,277, from Hidalgo, is apparently the same plant in a less 

 mature condition. It was distributed as C. gracillima. 



iProc. Amer. Acad. 18: 1S6. 1883. 



