

76 BOTANY OP THE DEATH VALLEY EXPEDITION". 



The dead branches of Larrea remain for many years without decomposing, and, 

 although seldom more than 2 or 3 cm. in diameter, furnished the principal fuel used 

 in the desert by the expedition. 



Larrea tridentata is the most important zonal plant of the Lower Sonoran zone, 

 growing with great uniformity over nearly the whole area of the desert region. We 

 crossed its western limits at Hesperia, on the northern slope of the San Bernardino 

 Mountains ; at the altitude of 975 meters in Antelope Valley, about 8 kilometers west 

 of Willow Spring; at the mouth of Tehachapi Canon; and on the eastern slope of 

 Walker Pass, at 1,160 meters. North of Walker Pass it finds its western limit at the 

 eastern base of the Sierra Nevada as far as Owens Lake. North of that point the 

 altitude of the region is too great and the plant does not occur, the line marking its 

 northern limit turning eastward across the desert. Dr. Merriamhas traced this lino 

 across California and Nevada to the southwestern part of Utah. 



The upper limits of Larrea in some of the desert mountains have been worked out, 

 as follows: on Browns Peak, 1,325 and 1,370 meters; on Lone Willow Peak, 1,430 

 meters; west of Amargosa, on the north slope of a peak in the Funeral Mountains, 

 1,310 meters,: on the western side of the Charleston Mountains, at 1,525 meters on a 

 west slope and 1,415 meters on a north slope; on the eastern slope of the same range, 

 at 1,370 meters; inthe Panamint Mountains, near Johnson Canon, atl,700 meters; in 

 Surprise Canon, at 1,575 meters; in Mill Creek Canon, at 1,400 meters. Specimens 

 were collected near Hesperia (No. 50) ; near Daggett (No. 158) ; and at Furnace Creek 

 Ranch, Death Valley (No. 467). 



A more detailed account of the distribution of this shrub is given by Dr. Mer- 

 riam in the general report. He found it along its northern limit in Oasis Valley, 

 Grapevine Canon, Indian Spring Valley, Pahranagat Valley, Virgin Valley, and 

 valley of the lower Muddy, in Nevada; and the Santa Clara Valley, in Utah. 



GERANIACEJE. 



Geranium richardsonii Fisch. & Traut. Ind. Sem. Petrop. iv. 37 (1837). Type 

 locality, 1 "vallies in the Rocky Mountains." 



In the Sierra, Nevada (Nos. 1378, 1834, 2102). Professor Greene 2 has pointed out 

 that this species, in California, grows at higher altitudes than G. incisum and in 

 moister soil. 



Erodium cicutarium (L.) Sp. PI. ii. 6S0 (1753), under Geranium; Ait. Hort.Kew. 

 ii. 414 (1789). Type locality European. 



Erodium moschatum, the commoner species in the coast region of California, 

 was not seen east of the Sierra, Nevada, and probably does not occur in the deserts 

 of the Great Basin. E. cicutarium was found to be of frequent occurrence in the 

 desert, along the routes traveled by wagons. It seldom, however, grew large enough 

 to be valuable for forage. Specimens were collected at San Bernardino (No. 34), 

 near Hesperia (No. 49), and in Johnson Canon, l'anamint Mountains (No. 514). 



RUTACEiE. 



Thamnosma montana Torr. & Frem. in Frem. Second Rep. 313 (1845). Type 

 locality, "inthe passes of the mountains, and on the Virgen river, in Northern 

 California" [now Nevada]. 



The odor of the bruised herbage of Thamnosma, when fresh, is penetrating rank 

 and offensive; but the smell persisting about, the, dry plant, in delicate and sweet. 

 The season of blooming is not very fixed, for flowering plants were seen from Janu- 

 ary to April. It should be noted that the final word from which the name is 

 derived (dii/ivoc, shrub, and 'oafiij, odor) is feminine, and that, therefore, the spelling 

 "montanum," for the specific name, which is frequently used, but which was not 

 given with the original description, is incorrect. The plant occurred between Victor 

 and Stodda rd Wells (No. 151) ; between Daggett and the first divide on the road to 

 1 Hook. Fl. Bor. Amer. i. 116 (1830). »F1. Fran. 98~(1891). " 



