1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 457 



Gaillardia pulchella. 

 Lepachys columnaris, var. pulcherrima. 

 Gutierrezia Texana. 

 Selenium amphibolum. 

 Stephanomeria minor. 

 Verbesina encelioides. 

 JParthenium hysterophorus, 

 Heliomeris tenuifolia. 

 Characteristic of alkali flats or arid sandy bottoms, are : 



Atriplex canescens (under several forms), acanthocarpa, expansa. 



Suceda fruticosa and depressa. 



Spirostachys occidentalis. 



Acanthochiton Wrightii. 



Cladothrix lanuginosa. 



Varilla Texana. 



SAN ANTONIO. 



The flora of the valley of the San Antonio Kiver, near its head where 

 stands the town of San Antonio, being typical of that of the many valleys 

 which drain the surrounding' country, I shall, at the risk of repetition, 

 describe it with some detail. 



Many trees and shrubs leaf in March and, during the same month, 

 many native flowers can be collected. In April the vegetation is in its 

 prime ; masses of luxuriant timber spread over the valley, thick shrub- 

 bery of various shades of green covers the uplands, and a sward of 

 thin but nutritious grass carpets the ground. The pale green of the 

 Mezquit-clad hills, contrasting with the somber foliage of the valley, 

 is particularly striking. In May, plants begin to suffer from the 

 hot and dry atmosphere. Before August, when summer rains usually 

 begin, the scant grass has become parched, the shrubbery temporarily 

 withered and the timber dimmed with dust. The first showers, how- 

 ever, quicken everything back to life. The winter temperature seldom 

 falling below 20°, many ornamental shrubs prosper in gardens, and 

 hardy rosebushes blossom all winter. 



The homely but useful Mezquit (Prosopis juliflora), here as everywhere 

 in South and Western Texas, is predominant ; it is mostly a shrub, 

 sometimes a stunted tree, and covers the slopes and many of the table- 

 lauds. Mixed with it are the hardly less common Lote-bush (Zizyphus 

 obtusifolius) andJBrasilor Blue Wood (Gondaiia obovata), two Rhamna- 

 ceous shrubs growing together and similar in appearance. To the same 

 order belong also Rhamnus Carolinianus, a tall shrub in shady places, 

 and Colubrinia Terensis, a low bush on higher ground near the head of 

 the river. 



Perhaps the tree most characteristic of San Antonio, and the pride 

 of its inhabitants, is the Huisache (Acacia Farnesiana) which thrives 

 everywhere in the valley, filling the air, in March and April, with the 



