464 BOTANICAL GEOGRAPHY.. 



shrubby Chenopodiacese, with which in tracts Artemisias are mixed, and along 

 the Sierra Nevada, and to the south of the 41st degree of latitude, Ephedra 

 occidentalis, forming an evergreen shrub. The most common of the Cheno- 

 podiacese found here is also Sarcobatus vermicularis ; Obione is next mentioned, 

 of which Obione rigida Torr. and Fr., with another new species, occurred at 

 Utah ; Salicornia also covered the banks of this lake. The woods of the 

 boundary-mountains to the north of Utah consisted of deciduous trees : 

 Populus, Salix, Quercus, Cratagus, Alnus, and Cerasus. Below the 39th de- 

 gree of longitude, the Sierra Nevada was crossed with great difficulties in 

 the depth of the winter, so as to reach the valley of Sacramento. The lowest 

 forest-zone on the desert side of the mountains consisted of a pine, the seeds 

 of which were edible, Pinus monophylla Torr., a tree from 12' to 20' in height, 

 and with a stem at the most 8" in diameter, which, with some roots and the 

 salmon found in the waters, form the food of the Indians. Further upwards 

 this pine (nut-pine) was found somewhat larger, its diameter amounting to 

 15". But it was not until an altitude of 6000' had been reached, that 

 Coniferous forests of a taller growth and of a different species were met with, 

 accompanied by a more luxuriant vegetation, in which the first indications of 

 a fairer climate were met with, At 8000' the trees were almost as gigantic 

 as in Oregon : red pines as high as 140' and 10' in diameter (Pinus Colorado 

 of the Mexicans) predominating, and with them tall cedars 130' in height, 

 and two species of fir of an equally tall growth (white spruce and hemlock 

 spruce). Trap-rocks form the fertile soil of these splendid tall forests, to a 

 considerable depth. On the west side of the mountains, below the Coniferous 

 zone, Fremont arrived at a region of evergreen and other oaks, which corre- 

 sponds with Hinds's representation of the character of the region of St. Fran- 

 cisco : here, after the impressions left by the deserts, the traveller was de- 

 lighted with the most luxuriant spring flowers in the valleys of the Sacramento 

 and St. Joachim. 



On his return, Fremont crossed over the Californian Andes by a much 

 lower pass, below the 36th degree, and travelling parallel with the Colorado, 

 on the southern border of the salt-desert, returned to the Great Salt-lake and 

 the Rocky Mountains. This road, which forms the course taken by the 

 caravans in going from New Mexico to California, was rocky and mountainous 

 (sloping off towards the Colorado from about 5000' to 2000') : the vegetation 

 was scanty, corresponding to the character of the flora of California. A 

 tall Zygophyllaceous shrub (T^ygoph. calif or nicum Torr., Fr.), a Yucca, and 

 numerous Cacti constitute the principal forms of plants over extensive tracts ; 

 and from the north towards this part, as far as the woods of the Yucca, the 

 Artemisia tridentata of the steppes extends : the traveller would not, however, 

 give the preference to the former, since the stiff and unsymmetrical form of 

 the Yucca appeared to him the most repugnant formation in nature. Among 

 the shrubs of this region, he mentions Ephedra occidentalis, Garrya elliptica, 



