1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 149 



Tol. VIII, ]¥o. 39. TFashing^ton, D. C. IScpt. 33, 1885. 



REPORT ON THE FLORA OP "WESTERN AND SOUTHERN TEXAS. 

 By Dr. V. HATAKD, U. 8. A. 



The observatioDS and collections on which the following report is 

 based were made at the several posts where I have been stationed since 

 August, 1880, also, and chiefly, while on duty with the expeditions for 

 the exploration of Western Texas, under the command of Maj. William 

 K. Livermore, chief engineer officer, Department of Texas, in the sum- 

 mer and fall of 1881 and 1883. The specimens themselves will be pre- 

 sented to the National Museum. 



The first part describes in a general way the vegetation of Western 

 and Southern Texas. The various topographical features of the land 

 are considered separately and their botanical physiognomy sketched as 

 accurately as possible. It includes such meteorological notes as were 

 deemed useful for the better understanding of the subject. 



The seconfi part is made up of economic notes on the plants known to 

 have useful or baneful i^roperties or to be of value to agriculture or in- 

 dustry. 



My grateful acknowledgments are particularly due to Mr. Sereno 

 Watson, of Cambridge, and Dr. George Vasey, of the Department of 

 Agriculture, for their valuable assistance in the determination of spe- 

 cies. 



PAKT I. 



GENEEAL VIEW. 



Austin, the capital of Texas, lies within the timbered agricultural 

 section of the State. South and west of it, the mean annual temperature 

 increases while the rainfall decreases so that a change of vegetation soon 

 becomes perceptible. San Marcos and New Braunfels are still centers 

 of prosperous farming districts ; farther south the success of qvo^ is 

 not so assured. After crossing the Guadalupe the change of climate is 

 marked and becomes more and more striking. The timber grows thinner 

 on the prairies, seldom extending far from valleys or water-courses ; 

 broad plains are covered with Mezquit, so characteristic of a serene, 

 rainless sky. West of the Colorado and San Antonio Rivers, and south 

 of the latter, farming is only remunerative on bottom-lands of valleys; 

 it ceases, practically, west of the headwaters of the San Saba, Llano, 

 and Nueces, and south of the Frio, or is only possible in rare valleys 

 with irrigation. 



Dallas and Fort Worth stand in the midst of a fine agricultural 

 Proc. Nat. Mus. 85 29 



