BOTAXICAL LABORATORY IX THE DESERT. 329 



T 



A BOTANICAL LABORATORY IN THE DESERT. 



By Professor FRANCIS E. LLOYD, 



TEACHERS COLLEGE, COLUMBIA UNIVERSITY. 



WO years ago the Carnegie Institution determined to establish a 

 laboratory to be devoted to the special study of desert vegetation. 

 The plan originated with Mr. Frederick V. Coville, who, under the 

 auspices of the Smithsonian Institution, had for some dozen years pre- 

 viously been a close student of the plants of the southwestern Ameri- 

 can desert. His interest was fixed by his experiences as a member of 

 the memorable Death Valley Expedition of 1891. After Mr. Coville's 

 plan had been adopted by the Carnegie Institution, an advisory board, 

 consisting of Mr. Coville and Dr. D. T. MacDougal, was appointed. 

 The first work of this board was the choice of a proper site — a task 

 which will be conceded to be neither easy nor unimportant when the 

 great extent and variety of the North American Desert is appreciated. 

 Both of these gentlemen were, however, possessed of wide personal 

 knowledge and experience of this region and brought to the solution 

 of the problem ripe judgment. After a further personal examination 

 of all of the most promising areas, including the deserts of Texas, 

 northern Chihuahua and Sonora in Mexico, New Mexico, Arizona and 

 of California, the choice rested upon Tucson, in southern Arizona. The 

 results of this investigation are embodied in an extensive report* which 

 is full of valuable data and most instructive and beautiful illustra- 

 tions. The wisdom of the choice of the advisory board may very 

 naturally be questioned, and I confess to have entertained some doubt 

 in this regard. After a personal examination, however, of nearly all 

 the above mentioned regions, and after spending the major portion of 

 the past summer at the Desert Botanical Laboratory, I am now of the 

 opinion that the action was Avell-advised and is fully justified. I am 

 therefore taking occasion at this time to give an account of the labora- 

 tory and its surroundings from my own point of view. 



The city of Tucson, with a population of 10,000, is situated in the 

 valley of the Santa Cruz. Its position is central with respect to the 

 deserts of California, Mexico, Texas, New Mexico and northern 

 Arizona. With an elevation of 2,390 feet above sea level, it has a 

 hot, though dry and bracing, climate. The soil is a fine clay or adobe, 

 underlaid by a white hard pan, locally known as caliche. Two miles 



* ' Desert Botanical Laboratory of the Carnegie Institution,' Publication 

 Xo. 6, November, 1903. 

 VOL. lxvt.— 22. 



