l!^*.'..] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 487 



pubescens), sparingly seen as a shrub or small tree on the summit; Frax- 

 inus jnstacice/oUa, shrub or small tree from 10 to 30 feet high, gen- 

 erally near water ; the Wild Mulberry {Morus microphylla), in canons, 

 mostly small, an exceptional specimen (with very small, undivided 

 leaves), measuring 15 inches in diameter ; a Maple (Acer grandidentatum)^ 

 uncommon shrub or middle-sized tree, in caiions, also found in the Organ 

 Mountains; J.c«cm Greggii, small tree, oftener a shrub ; a Maguey {Agave 

 Wislizeni*), which may be placed here, very common on the slopes but 

 smaller than the form of the same species growing in the Chenate and 

 Chisos Mountains. 



To this list we should add, as usual, the Mesquite, Hackberry, Soap- 

 berry, i!^ogal, and Mexican Buckeye. 



The principal and characteristic shrubs, or bushy ligneous plants, 

 are: 



On the summit : 



Cercocarpus parvifolius. 



Symphoricarpus rotundifolius and longiflorus. 



Whipplea Utahensis. 



Rihes viscossissimum. 



Neillia Torreyi. 

 In caiions : 



Ptelea trifoUata. 



Rhamnus Purshiana. 



Lonicera dumosa. 



Fendlera rupicola. 



Forestiera NeoMexicana. 



Rohinia Neo-Mexicana. 



JSophora secundifiora. 



Vitis riparia. 



Ampelopsis quinquefolia. 



Berheris Fremonti and r^ens. 



AstrophyUum dumosum. 



Brickellia hnecharidea. 

 On foot-hills : 



Dalea formosa. 



Acacia constructa. 



Mimosa Muncifera. 



Ceanothvs Greggii. 



Cercocarpus parvifolius, var. paucidentatus. 



Prunus CapuU f 



Spirea ccespitosa (crevices of rocks). 



Garrya ovata (first time collected in U. S.). 



Kramer ia parviflora^ var. ramossissima. 



* Referred to this species by Dr. Engelmann. This is the Maguey found in all the 

 mountains of Western Texas. It is allied to A. Americana and A. Parryi, but well 

 distinguished from both. 



