316 PROCEEDINGS OF THE AMERICAN ACADEMY 



XVIII 

 CONTRIBUTIONS TO AMERICAN BOTANY. 



By Sereno Watson. 



Presented May 5, 1882. 



1. List of Plants from Southwestern Texas and Northern Mexico, col- 

 lected chiefly by Dr. E. Palmer in 1879-80. — I. Polypetalce. 



Dr. Edward Palmer's present collection was made during the 

 last six months of 1879, mostly in the region lying northwest of San 

 Antonio, Texas, and along the routes from that place to Laredo and 

 Eagle Pass upon the Rio Grande, and during the following year in 

 the States of Coahuila and Nuevo Leon in Mexico. A nearly com- 

 plete set of these plants was sent to the herbarium at Kew, England, 

 and a partial list was there somewhat hastily made, which is the basis 

 of the present one. In addition, determinations are given of an 

 excellent collection made by Dr. J. G. SchafFner in the State of San 

 Luis Potosi (likewise partially named at Kew), as well as of some 

 plants received from Professor Alfred Duges of Guanajuato, and as 

 occasion serves the numbers of the previous collection of Parry & 

 Palmer in Northern Mexico are also cited. The numbers under 

 which Palmer's collection was distributed by him are included in 

 parentheses under the species. The Cactacece have been kindly 

 named by Dr. Engelmann, so far as their determination was possible, 

 and continual use has been made of the recent catalogue of the Mex- 

 ican flora by Mr. W. B. Hemsley in the botanical volumes of the 

 " Biologia Centrali- Americana " of Godman and Salvin, which has 

 proved a very material assistance. 



Clematis Drummondii, Torr. & Gray. At Uvalde, Texas (3), 

 and Parras, Coahuila (1) ; also specimens with smaller leaves from 

 Laredo on the Rio Grande (2), nearly equivalent to C. nervata, 



