478 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1335. 



dotted with white bunches of Common Grama interspersed among thick 

 patches of Lechuguilla. About their bases are thickets of Atriplex 

 acanthocarpa and canescens; Selinoiarpus diffusus, Ephedra, Larrea, Flou- 

 rensia; more rarely Clappia suwdwfolia, and always more or less Cactacece. 

 Somewhat special to the gravelly hills of the Great Bend are: Ayenia Mi- 

 crophylla, Cladothrix suffriiticosa, Bouchea spathulata, Cowania ericcefolia, 

 Boerhaavia eriosolena, Hibiscus Coulteri, H. denudatus (var. involucellata), 

 Lycium pallidum, Prunus minutiflora. On the bluffs of the Eio Grande, 

 south of the Chisos Mountains, mixed with Lechuguilla and nearly as 

 forbidding, was collected a new species of a genus not before observed 

 in the United States — Hechtia Texensis, Watson. 

 Mesas are covered with : 



Prosopis jul i 'flora. 



Zizyphus obtusifolius. 



Condalia obovata and spathulata. 



Larrea Mexicana. 



Ephedra antisiphylitica and trifurca. 



Flourensia cernua. 



Kceberlinia spinosa. 

 The Leucopyhllum Texanum, so strikingly beautiful with its purple 

 flowers and white foliage, is very abundant on high plains west of 

 Uvalde ; in the Great Bend it is often mixed or replaced by its still 

 handsomer kin Leucophyllum minus. Likewise highly ornamental is the 

 s pi nose Parkinsonia Texana on the Lower Eio Grande, and the scented 

 Buddleia marrubiifolia farther west. 



Other shrubs likewise common, and characteristic of bluffs and high 

 mesas, are : 



Acacia Berlandieri, Greggii, constricta, amentacea. 



Cassia Wislizeni (west of the Pecos). 



Mimosa biuncifera^ borealis, Lindheimeri, dysocarpa, monancistra. 



Eysenhardtia amorphoides. 



Dalea formosa. 



Forestiera angustifolia, Neo- Mexicana, pubescens (east of the 

 Pecos). 



Salvia balloto?flora. 



Goldenia Greggii, canescens, hispidissima. 



Lippia lycioides, ^Yrightii, graveolens. 



Cercocarpus parvifolius. 



Talinopsis frutescens. 



Castela Nicholsoni. 



Microrhamnus ericoides. 



Krameria canescens, parvifolia, lanceolata. 



Berber is trifoliata. 



Parth eni u m inca num . 

 Yucca rupicola (east of Devil's Eiver). 

 Of herbaceous plants, the most conspicuous belong to the genera 



