50 NTRIBUTION8 KBOM THE NATIONAL SBBBAB1UM. 



isolated mountain ranges of less extent rising up out of the midst of 

 west Texan, New Mexican, and Arizonian deserts, which might be 

 even more prolific of Ptelea species. The Grand Canyon of the Colo- 

 rado and it- tributary gorges seem to abound in them, all hitherto 

 undescribed; and the same is true in respect t<> other extensive dis- 

 tricts, all quite different one from another, in Utah, New Mexico, 

 ( Colorado, and ( Jalifornia. 



The distributions of Mexican plant specimens, so copiously made l>v 

 Mr. Pringle and by Dr. E. Palmer during forty years past, include 

 no small number of Ptelea-, all of which, until within the last year, 

 have been sent forth without any critical examination at all under the 

 one convenient name of /'. angustifolia, while of that species it-elf 

 neither of the noted explorers and collectors named appears ever to 

 have obtained a specimen. 



At different times within the last twenty-five year- the present 

 writer ha- gathered in several parts of New Mexico. Arizona, and 

 California members of this genus which he was never able to identify, 

 and which are herein first described. 



At the National Herbarium there is special wealth of material in 

 this a- in many another genus, which has been procured, as it were, by 

 special agents who have gone into many a remote and obscure cor- 

 ner of the West and brought back plant specimens of great value. 

 By wise prevision of the curators in botany, Mr. Coville and Dr. 

 Rose, the collecting of plants at least one set ha- been for years 

 enjoined upon field parties going from the Department of Agricul- 

 ture, the Geological Survey, the Bureau of Fisheries, etc.. to the 

 interior of the remoter territories; and as a result of such work our 

 plant collection i- rich beyond comparison in plants collected by this 

 mean-, which are to lie found in no other herbarium, whether of our 

 own count ry or any other. 



To the great wealth of specimens thus gathered hero. I have been 

 able to add. by courteous loan, the Ptelea specimen.- from the her- 

 barium of ('apt. John Donnell Smith, of Baltimore, those belonging 

 to the Parry Herbarium from the Iowa State College, and those of 

 the California Academy at San Francisco, in which also occur the 

 types of several new species. All of these last, received much more 

 than a year since, now by virtue of my prolonged retention of them 

 have escaped the sad fate that befell almost the whole of that priceless 

 herbarium in the recent earthquake and tire. 



In the earliest hours devoted to close inspection and comparison, it 

 became manifest that the real characters for species in Ptelea had 

 never yet been indicated or apprehended. In other genera of woody 

 growths, the oak-, for example, he who would distinguish and arrange 

 the species could do nothing were he to leave unnoticed and unnoted 

 the color and other characteristic- of their trunks, their branches, and 



