40 



bracts narrow, glandular; pedicels 1-2 cm. long, glabrous; 

 stamens about 20, with white anthers : pome pyriform up to the 

 time of ripening, when fully ripe obovoid to spherical, but often 

 drying pyriform, a little more than i cm. in diameter and a little 

 longer than thick, dull red with green blotches. 



The tree flowers about the middle of May, and the fruit ripens 

 in early October. 



According to Mr. Canby's observations, the plant is not un- 

 common in the vicinity of Tanners\ille. 



N. L. Britton. 



REVIEWS 



The Desert Botanical Laboratory of the Carnegie Institution'^ 



This volume contains the report of the advisory board, con- 

 sisting of Mr. E. V. Coville and Dr. D. T. MacDougal, which 

 was appointed to investigate the selection of a site for the Carnegie 

 Desert Laboratory in the aiid regions of the West. The report 

 will be of unusual interest to botanists, not only because it deals 

 with one of the most important botanical departures in this country 

 and promises results of the highest biological importance, but 

 also because the authors have given sufficient knowledge of the 

 flora and conditions prevailing in these arid belts to reveal the 

 wealth of material afforded for physiological and geographical 

 study. The majority of botanists have not had the opportunity 

 of visiting the areas covered by the report and to such and to 

 people in general the diversit)' of climate, topograph)^ mechan- 

 ical, chemical and physical conditions which obtain in these 

 desert districts will come with something of surprise. The 

 information concerning the areas and distribution of these arid 

 regions in the Chihuahua and the Sonora-Nevada desert belts, 

 which occupy more than a million scjuarc miles of plateaus and 

 plains east and west of the main Cordilleran ranges together with 

 data upon the meteorolog)- and othci- conditions controlling plant- 

 life in these aix-as is an important sujjplcment to the meager and 

 often misleading current information upon this subject. 



* Carnegie Insliliilifni of Washington, I'liblicalion, No. 6. I'p. i-vi, 1-5S. //. 

 '-39 +/ ' -4- " ^ '903" [Issued J 1004.] 



