478 PKOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



dotted with white bunches of Common Grama interspersed among thick 

 patches of Lechuguilhi. About their bases are thickets of Atriplex 

 acanthocarpa and canescens; Selmocarims diffiisus, Ephedra^ Larrea, Flou- 

 rensia; more rarely Clappia sua;da'foUa,an(l always more or less Cactacece. 

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

 crophylJa, Cladotlirix suffrttticosa, Boiichea spathulata, Cowania ericcefoUa, 

 Boerhaavia eriosolena, Hibiscus Coulteri, H. denudatus {var. involucellata)^ 

 Lyciuin 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 : 



Frosopis j III i flora. 



Zizyphus obtiisifoUus. 



Condalia ohovata and spatliulata. 



Larrea Mexicand. 



Ephedra antisiphylitica and trifurca, 



Flourensia cernua. 



Kceherlinia spinosa. 



The Leucopylillum Texanmn, 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 

 ispinose 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 hiuncifera, horealis, Lindheimeri, dysocarpaj monancistra. 



Eysenhardtia amorpJioides. 



Dalea formosa. 



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

 Pecos). 



Salvia ballotwflora. 



Coldenia Greggii, canescens, hispidissima. 



Lippia lycioides, Wriglilii, graveolens. 



Cercocarpus parvifolius. 



Talinopsis frutescens. 



Castela Nicholsoni. 



Microrh am 7ius ericoides. 



Krameria canescens, parvifolia, lanceolata. 



Berberis trifoliata. 



Parthenium incanum. 



Yucca rupicola (east of Devil's Eiver). 

 Of herbaceous plants, the most conspicuous belong to the genera 



