1885.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 481 



Vol. Till, Wo. 31. Washington, D. C. Sept. 23, 1885. 



Euphorbia versicolor. 



Aphora Neo-Mexicana. 



Phyllanthus polygonoides. 



Argyrothamnia Neo-Mexicana. 



(Enotliera Eartwegi and Greggii. 



Mentzelia nuda. 



Hoffmanseggia stricta and Jamesii, 



Dalea nana. 



Psoralea tenuifiora. 



Collomia longiflora. 



Plantago Virginica. 

 Also the following Composites : 



Riddellia tagetina. 



Gutierrezia eriocarpa. 



Steplianomeria minor. 



Grindelia squarrosa. 



Helianthus cUiaris. 



Melampodium cinereum. 



Thelesperma gracile. 



Gaillardia pule hell a. 



Pedis angustifolia and papposa. 



IAndlxeimeria Texana. 



Zinnia grandiflora. 



Lygodesmia aphylla. 

 And the following Grasses : 



Bouteloua oligostachya, hirsuta, racemosa, eriopoda. 



Aristida purpurea and stricta. 



Andropogon sa cch a ro ides. 



Chloris cucullata. 



Eragrostis powoides, var. megastachya. 



On the bluffs edging the northeastern border of the Plains, we find a 

 few Xut Piue (Pinus edulis), many straggling groves of small Cedar 

 (Juniperus occidental}*), dwarf Gray Oak (Quercus grisea) and var. pun- 

 gens of Q. undulata. The grass is abundant and nutritious. 



West of Odessa, about 20 miles, the sand zone begins, running south 

 and east nearly to the Pecos, and north to the very center of the Plains. 

 In this zone are the Sand Hills, a dreary, chaotic belt of reddish sand tossed 

 by the wind into hillocks, cones and ridges of various sizes and shapes. 

 In these dunes I found but four shrubs : Mezquit, of a rather vigorous 

 growth, hinting at the presence of water in some substratum within 

 the reach of its long, penetrating roots; a ; 'Shin" Oak, form closely 

 allied to var. Jamesii of Quercus undulata, spreading into a low thicket, 

 with shallow, strongly tuberculated cups and very large, edible acorns ; 

 Proc. Nat. Mus. 85 31 



