1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 479 



Mentzelia, (Enothera, Boerhaavia, Acleisanthes, Dalea, Cassia, Greggia, 

 Vesicaria, Abutilon^ Menodora, Eriogonum, Croton, Euphorbia, Biddellia, 

 Baileya, Zinnia, Liatris, Aplopappus, Pedis. 



In ravines and canons are commonly seen several pretty trailers like 

 Janusia gracilis, Bhynchosia Texana, Phaseolus angustissimus and atro- 

 purpureus ; the Scarlet Sage (Salvia Greggii), the showy Tecoma stans, 

 and Eucnide bartonioides. 



Cactacem are never wanting on broken uplands ; the most common 

 species are : Mamillaria macromeris, meiacantha, tuberculosa, Heyderi ; 

 Cereus stramineus, the noted Strawberry Cactus, under several forms; 

 G. chloranthus, paucispinus, enneacanthus ; Echinocactus longehamatus 

 (Turk's Head), often a foot in diameter, yielding delicious fruit hardly 

 inferior in size or quality to that of Cereus stramineus ; E. horizonthalo- 

 nius, intertextus ; Opuntia frutescens, arborescens, Grahami, and several 

 flat-jointed species. 



Nutritious Grasses, often sparse or absent in valleys, generally cover 

 bluffs and hills. The Common Grama (Bouteloua oligostachua) is by far 

 the most abundant. Other common species are Bouteloua hirsuta, poly- 

 stachya and Havardi; Cathestechum erectum (first time collected north 

 of the boundary line) ; Andropogon scoparius and saccharoides ; Aristida 

 purpurea and dispersa ; Elionorus ciliaris ; Muhlenbergia distichophylla. 



STAKED PLAINS. 



Under the name of Staked Plains is comprised the vast, rather ill- 

 defined plateau south of the Canadian River Basin and east of the Pecos; 

 this river, bending eastward, also forms its southwest boundary. It 

 ends abruptly, by a sudden fall of several hundred feet, on the north 

 where drained by the Canadian, and on the east where drained by the 

 many heads of the Brazos and Eed River. Judging from the general 

 direction of the water-courses, this plateau slopes down insensibly to- 

 wards the south and east. There is no topographical feature separating 

 it on the southeast from the sandy plains of the Colorado and Concho 

 Rivers. On the Texas Pacific Railroad, the traveler may be said to 

 enter the Staked Plains at about Big Spring, although, at this latitude, 

 the escarpment so conspicuous farther north- is hardly perceptible. 



There is no stream on the Plains. Salt lakes, ponds and holes, rarely 

 fresh-water springs, are found in the long- winding canons and valleys 

 which open into the rivers named above. At several places along the 

 Texas Pacific Railroad excellent water in fair abundance was struck 

 at a depth of about 50 feet. It is quite probable that water could be 

 obtained by digging or boring over many portions of the Plains. The 

 western belt, along the Pecos, unsuccessfully bored by Captain Pope in 

 1856, seems in this respect the most unpromising. 



The Northern Plains consist mostly of level or undulating prairies 

 covered with good grass. Large bodies of cavalry have several times 



