494 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. [1885. 



vine Creeks. Into these, and the Rio Grande, empty many canons and 

 ravines containing more or less Hackberry, Willow, Nogal (Juglans ru- 

 pestris), Buckeye ( Ungnadia speciosa), Sumac {Rhus copallina and virens), 

 and Mulberry (Moms microphylla); sometimes, Cottonwood and Texas 

 Green Ash, shading springs. The uplands bear scattered clumps of Ce- 

 dar and Gray Oak. These general remarks apply to the range of smooth, 

 grassy bluffs extending to Los Alamos de Cesario Creek ; thence to 

 Agua Fria, the country is more rocky and barren. 



CHISOS MOUNTAINS. 



The Great Bend of the Rio Grande, extending from the Tarlinga on 

 the west, to the Maravillas on the east, is, with the exception of parts 

 of the Staked Plains, the most sterile and unattractive region of West 

 Texas. The Eossillo Mountains are the best part of it and the only one 

 where the grazing of large herds is at all possible. They are covered from 

 base to summit with fine grass in ordinary seasons, and have four or 

 five permanent springs, two or three of which are shaded with Cotton- 

 wood. 



The Chisos Mountains are very imposing from their height and bulk. 

 They contain a fair amount of small timber and their valleys and slopes 

 are lined with good grass, but, owing apparently to their geological for- 

 mation, are so destitute of permanent water as to preclude their settle- 

 ment by stockmen. The broad plains surrounding them are barren and 

 dreary in the extreme. 



The only Pine on the Chisos is the Nut Pine (Pinus edulis) which 

 covers the summits and many of the upper slopes; it is often a foot 

 in diameter and 40 feet high. With it are two species of Cedar, shrubs 

 or small trees, Juniperus occidentalis and J.flaccida, the latter not be- 

 fore observed north of the Rio Grande. 



In valleys, the Texas Red Oak (Quercus rubra, var. Texana), a medium 

 tree, is the prevalent kind. Gray Oak (Q. grisea), of small size, is com- 

 mon on foot-hills. Quercus Emoryi, of medium size, occupies almost ex- 

 clusively several of the canons. More rare is Q. Durandii. 



Other trees seen in high canons, but uncommon, are: a Maple {Acer 

 grandidentatum), also growing in the Guadalupe and Organ Mountains ; a 

 Cherry-tree (Prunus Capuli), both of medium size; and an Ash (Fraxinus 

 cuspidata) somewhat smaller. 



Of shrubs the following are sparingly found: 

 Cercis reniformis. 

 SopJiora secundiflora. 

 Arbutus Xalapensis. 

 Sambucus Canadensis. 



Bhamnus serrulata (new to the United States). 

 Spiraea discolor. 



