THE TULAROSA DESERT 5 



From the dunes toward Samalayuca the valley bottom has a vegeta- 

 tion of mesquite mixed with Zizypkus, Koeberlinia spinosa, and Atri- 

 plex canescens. An annual Croton forms a thick spindle shaped 

 tumble weed adapted for rolling only along one axis. 



The highest part of the dunes is not crossed by the railroad but lies 

 east and southeast from Samalayuca about five miles and apparently 

 rises 200 to 300 feet from the plain. 



About nine pounds of the material of which the dunes were com- 

 posed was collected by removing a thin surface layer and then placing 

 in a cloth waterproof bag. This material was forwarded to Dr. W. 

 J. Gies, consulting chemist to the New York Botanical Garden with 

 the request for an analysis. Dr. Gies' report is printed on pages 10 and 

 II of this pamphlet. 



THE TULAROSA DESERT. 



Starting westward from Alamogordo, New Mexico, across the 

 Tularosa desert, one first enters a region characterized by low 

 mesquites, commonly 3 to 6 feet high, with an abundance of Atriplex 

 canescens and Koeberlinia spinosa. That the soil is alkaline is in- 

 dicated by a surface deposit along an irrigating ditch. The ground 

 bears also an abundance of a suffrutescent Suaeda^ a bunch Sporobolus 

 with expanded panicles, and occasional specimens of a Lyciuni. In 

 low spots and along the margins of clay bottomed washes, an incrus- 

 tation of alkali appears, accompanied by Allenrolfea occidefitalis. 

 In this area water is commonly found in wells at a depth of 50 to 70 

 feet. Toward the middle of the valley the mesquite disappears, and 

 the principal bush vegetation is Atriplex canescens^ with a great deal 

 of the Sporobolus and areas in which Tucca radiosa (Plate II), or 

 Opuntia arborescens^ or another Opuntia^ conspicuous at this season 

 by its scarlet fruit, are abundant. The wagon road in this part of 

 the valley often strikes at the depth of a foot the so called caliche rock, 

 a sort of hardpan. Ground water is presumably to be found only at a 

 great depth. 



Our principal object on this trip into the Tularosa desert was to 

 examine the flora of a remarkable area of drifting sand it contains, 

 known as the White Sands, composed not of silica but of gypsum, and 

 estimated to cover an area of 10 by 40 square miles (Plate III) . These 

 sands are most easily reached at a point about 20 miles southwest of 

 Alamogordo. Here there are some water holes where horses when 

 forced by continued thirst can be watered with safety. Water for men, 

 however, must be carried from Alamogordo. 



Two principal plant formations occur in the bottoms and the dunes 



