1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 495 



More common and characteristic are the following : 

 On slopes : 



Prosopis juliflora. 



Zizyphus obtusifolius. 



Cercocarpus parvifolius. 



Rhus virens, microphylla, trilobata. 



Forestiera a ngu s t-ifo lia. 



Lippia W r igh t ii . 



Bouvardia hirtella. 



Houston ia fasciculata. 



Dalea formosa. 



Calliandra eonferta. 



Acacia Rcemeriana, Greggii, constricta, filicina. 



Porliera angustifolia. 



Bernardia myricwfolia. 



Salvia chamcedryoides and Regla (new to the United States). 



Philadelphus microphyllus. 



Berberis Fremontii. 

 In valleys : 



Garrya ovata. 



Rhamnus Purshiana. 



Kozberlinia spinosa. 



Prunus minutiflora. 



Morus microphylla. 



Diospyros Texana. 



Gondalia Mexicana and spathulata. 



Mimosa biuncifera. 



Vngnadia speciosa. 



jSapindus marginatus. 



Abundant are Lechuguilla, Maguey, and Sotol. The former (Agave 

 heteracantha) infests the foot-hills, and, in places, extends up high 

 slopes where it mingles with the latter (JDasylirion Texanum). The 

 Maguey [Agave Wislizeni), already noticed in other mountains, thrives 

 in high altitudes, even on the very summit. Its stem is from 3 to 5 

 inches in thickness, 13 to 18 feet high, and bears from eight to sixteen 

 panicles. 



To these plants should be added the usual Yucca baccata and angusti- 

 folia, Nolina erumpens and Texana, and the bushy Composites: Rymena- 

 therum acerosum, Zexmenia brevifolia, Trixis angustifolia. 



Of the Cactacae the most prominent representative is the noted Straw- 

 berry Cactus (Cereus stramineus), with large, luscious fruit. 



Of the many lignescent or herbaceous plants which characterize these 

 mountains, the following are most conspicuous : 



Carlowrightia linear if olia, common in arroyos. 

 Pentstemon barbatus, Fatoni, Havardi. 



