76 The Botanical Gazette. . [February, 
Botany of the Death Valley Expedition. 
This report not only deserves notice for its own sake, but also as 
representing the result of the first attempt by the government to con- 
duct a biological survey from the botanical standpoint. The result 
certainly indicates the great advantage of having trained botanists as 
well as collectors in the field. Compared with the usual bare lists, 
with such meager information as collectors have made _ possible, the 
present report belongs to an entirely different class. Mr. Coville is 
known to be very systematic, and the parts follow each other with all 
the precision and fulness of an encyclopedia. The summary shows 
that the catalogue contains 1,261 species and varieties, forty-two of 
which are characterized as new. Two genera are proposed as new, | 
viz.: Orochenactis (founded upon Chenactis thysanocarpha Gray) — 
and Phyllogonum (a peculiar member of the Eriogonez). /remonto- 
dendron is proposed as a substitute for Hremontia under the rule of 
homonyms. As interesting as is the catalogue of species, with its very 
full and very valuable notes, the most significant part of the report is 
that which deals with the principles of plant distribution in general, 
the distribution of plants in southeastern California, and the character» 
istics and adaptations of the desert flora. The treatment of the general 
subject of distribution is best indicated in the following summaly 
given by the author: 
‘To sum up, the six ultimate factors in the distribution of vegetation até 
heat, light, water, food, air and mechanique. These factorsare variously com 
bined in actual fact into such conditions, among others, as geographic isola 
lation, latitude, altitude, rainfall, soil, fires, proximity to large bodies of water, 
slope exposure, and presence of forests.’’ 
Attention is called also to the fact that trees and shrubs are the best 
zonal guides, as illustrated by the Larrea zone (Lower Sonoran), 
which occurs a Grayia belt. In treating of the distribution of plants 2 
S. E. California, the desert plants east of the Cordilleran system are 
considered, the plants of the high Californian Sierras (which were 
found to show as close an affinity to those of the Rockies of Colo- 
rado as to those of the Oregon and Washington Cascades, which is 
taken to indicate a former boreal communication across Nevat® — 
and Utah), and those of Death Valley proper. The last show, 7 - 
was to be expected, a northern extension of Sonoran and Chihue 
huan types. The characteristics and adaptations of the desert f0% | 
*COVILLE, FREDERICK VERNON:—Botany of the Death Valley Expedition. | 
report on the Botany of the Expedition sent out in 1891 byt ‘ 5 ath Valley, 
4 is ea St ae 
ons U. . 
+z 
California. 8vo. pp. 318, with 21 plates and map. Contributi 
Herbarium, Vol. IV, 1893. ; “ 
