﻿632 CALIFORNIA ACADEMY OF SCIENCES. 



Psoralen mephitica Wats. 



No. 5082a. April 20, 1894, Pagumpa, Arizona. 4000" 

 alt., in gravelly clay. 



No. 5098b. April 23, 1894, to P °^ g ra d e above Pa- 

 gumpa, Arizona, 5,000° alt., in gravelly clay. 



No. 5095. April 21, 1894, Pagumpa, Arizona, 4000° 

 alt., in gravelly clay. 



This is the plant referred to by me in my Contributions 

 in Zoe as P. castorea. An examination of duplicate type 

 specimens of the latter species shows that Watson was 

 mistaken in both his description of the latter species and 

 in the locality at which it was collected. Watson mistook 

 the bracts for the calyx lobes, and gave as the locality 

 where the plants, were collected " Beaver City, Utah," 

 adding (doubtless on the authority of Dr. Palmer) the 

 statement that both species grew together. This is er- 

 roneous. Dr. Palmer never collected any plants at Beaver 

 City, Utah, during the year in which he collected these 

 species, but he did collect in that year in the Beaverdam 

 Mountains on the northeastern corner of Arizona at a 

 place called Beaverdam. On the drifting sand dunes at 

 Beaverdam Dr. Palmer collected P. castorea probably at 

 the end of his day's journey, that being the first place in 

 which water can be secured west of the Beaverdam 

 Mountains, and therefore must have been his camping 

 place for the night. During the earlier part of the same 

 day along the road he must have collected P. mephitica 

 among the junipers high up on the mountains in a wholly 

 different zone from that of the Larrea belt in which the 

 former was collected. The difference in elevation at 

 which the two species grow is over 3000 ft. P. mephitica 

 never grows in loose sand but always on rocky or gravelly 

 places and is remarkable for its long, tuberous-thickened, 

 branched, woods, and interlaced roots, forming broad 

 patches among the junipers. 



