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ART. IX. — Plantce Prattenianaz Californicm : An enumeration of a collection of Cali- 

 fornia Plants, made in the vicinity of Nevada, by Henry Pratten, Esq., of New Har- 

 mony ; with critical notices and descriptions of such of them as are new, or yet unpub- 

 lished in America. 



By Elias Durand. 



This collection, which was placed in my hands by the Philadelphia Academy of 

 Natural Sciences in the latter part of last year, is composed of about two hundred 

 specimens, many of which, unfortunately, are in a very incomplete state. It was 

 made during the spring and summer of 1851, in the vicinity of Nevada, a place 

 situated on Deer Creek, one of the affluents of the Sacramento river, and occupying 

 an intermediate position between the mountains of the Sacramento and those of 

 Calaveras county. Nevada stands at an elevation of about three thousand feet above 

 the level of the Pacific Ocean, near the junction of the granitic and schistose rocks. 

 To the soil of the former, as well as to that of the porphyritic lavas, are confined the 

 large pines, firs and arbor-vitse, while the nut pines and acacias thrive only on the 

 schistose rocks. I am informed by Mr. Pratten that many of his plants belong, ex- 

 clusively, either to the granitic or to the schistose formations, whilst others grow indif- 

 ferently on both. 



Before entering upon a serious investigation of these specimens, I put aside all 

 those that were new to me, with the view of submitting them to my friends, Profs. 

 Torrey and Gray, who have had under examination several large collections of Cali- 

 fornia plants. To the great experience and friendly assistance of these learned 

 botanists I am highly indebted. They have been good enough to point out the species 

 which they had already described in manuscript, and to procure for me Bentham's 

 Plantce Hartwegiana, or descriptions of new plants collected by Hartweg in the moun- 

 tains of the Sacramento river — a publication extremely rare in this country, and in 

 which I found descriptions of many of the plants I had before me. 



All the new species of Mr. Pratten's collection, described either by Profs. Torrey, 

 Gray, Mr. Bentham, or by myself, amounting together to about forty, have been 

 united in this essay, and may be considered as new matter, not having been published 

 as yet in any American work. Whenever I have failed to obtain Professors Torrey 

 and Gray's notes, (their manuscript being in the hands of the printer,) I have 

 endeavored to supply this want by giving my own diagnosis. 



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