88 



BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Other striking plants of the Dog Mountains are 



Schigiiu'Ud nipestris (Liumieus) 



Spring. 

 Yucca baccata Torrey. 

 Dasylirion sp. 

 Agave palmeri Eiigelmann. 

 Nolina Jlndhehnertana (Scheele) 



Watson. 

 AiicDiopsis califoniica Hooker and Ar- 



nott. 

 Argemone mexicatia Linnjipus. 

 FaUugia paracloxa {D. Don) Endliclier. 

 Mimosa hiiDicifcra Bentbani. 

 Acacia filiciiloidcs (Cavanilles) Tre- 



lease. 

 Acacia constricia Bentham. 

 Cassia wislizeiii Gray. 

 Astragalus mollissimns Torrey. 

 Astragalus nuttalliauus de Candolle. 

 Krameria sccundiflora de Candolle. 

 Fouquicria splrndots Engelinann. 

 CoviUea tridentata (de Candolle) 



Vail. 



.Jutropha iiiacrorJiiza Bentham. 



Rlius irilohato Nuttall. 



Rhus inicrophylla Engelmann. 



Zizyphus sp. 



Yitis nrizonica Engelmann. 



Ccreus peciinatus rigidlssimtis Engel- 

 mann. 



Opuntia HiidJieiiiicri Engelmann. 



Opuntia filipcudula Engelmann. 



Opuntia arborcsceus Engelmann. 



Lyciuni pallidu))) Miers. . 



Auisacanthus thurbcri Gray. 



Cucurbita foctidissinia Humboldt, 

 Bonpland, and Knutli. 



Ibervillea lindheimeri (Cognlaux) 

 Greene. 



Baccharis ptcronioidcs de Candolle. 



Baccharis glutinosa Persoon. 



Crassiiia grandiflora (Nuttall) Kuntze. 



Perezia nana Gray. 



Trixis angustifolia de Candolle. 



Station No. 16. — "Whitewater, Chihuahua, Mexico. This camp 

 was located on the south side of an arroj^o, in which a shallow well 

 supplied us with very bad water, about a mile south of Monument 

 No. 61 and 246 kilometers (153 miles) from the Rio Grande, at an 

 altitude of 1,528 meters (5,013 feet), in the midst of the Whitewater 

 Hills, between the East and West Playas. In September, 1893, the 

 AVhitewater arroyo contained water. Animal and plant life were 

 abundant, and large collections were made. I occupied this station 

 May 30 and 31, June 2 and 3, June 13 to 22 and 27 to 29, 1892; Sep- 

 tember 10 to 15 and 23, 1893. Mr. Holzner was there June 13 to 22 

 and 27 to 29, 1892. 



Vegetation. — There were no forests in the immediate vicinity of 

 the station, the only trees being small mesquites and a few straggling 

 oaks, hackberry, mulberry, and wild china trees, together with the 

 desert yucca. On the neighboring East Playas and West Playas 

 valleys were extensive tracts occupied by mimosa and creosote bushes, 

 with the tapioca {Jatropha macrorliiza Bentham) and several kinds 

 of gourd {Ci(eu7-hita foztklissima Humboldt, Bonpland, and Kunth; 

 G. digitata Graj^; Apodantkera imdnlata Gray, and a species of 

 Ibervillea) in abundance. The plain and grassy hills surrounding 

 White Water abound with aloe, Nolina or bear-grass, Dasylirion, 

 yucca, acacia, senna, sumach, FaUugia, Trixis, and numerous species 

 of cacti, among which are Opuntia macrocentra Engelmann, 0. arhor- 

 escens Engelmann, and the beautiful rainbow cactus {Cereus pecii- 

 natus rigidissimvs Engelmann. 



