50 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [Yoi.vi. 



the Atlantic flora, has three or four species in the Texano-Arizonian 

 region, two of which enter the Great Basin, and one belongs to the 

 southern part of California. 



Taxink.i: are absent from the Rocky Mountain flora. The Atlantic 

 flora has the depressed Taxus Canadensis at the north, and an upright 

 arborescent and perhaps peculiar species in the northern part of Florida. 

 There is a similar one in the woods of the Pacific side of the continent. 

 The Atlantic flora possesses the original Torreya; California another; 

 the two remaining species are of Northeastern Asia. 



C pressinile. — The amphigsaan Juniperus communis traverses the 

 continent at the north ; and a prostrate form off/. Sabina probably does 

 the same; also J. Virginiana, the eastern Red Cedar. But on a south- 

 ern range the latter species hardly passes out of the Atlantic region. 

 J. occidentals and J. Californica are the characteristic species of the 

 mountains bordering and traversing the southern part of the Great Basin 

 and of California, Cupressus is wanting to the Atlantic and to the 

 Rocky Mountain floras, but there are three species in the Pacific flora. 

 Qhanuecyparis is of one species in the Atlantic flora, two in the Pacific, 

 the remainder in Japan. Thuja is of two species, one of the Atlantic 

 flora, the other of the Pacific and of Japan. Libocedrus is represented 

 by a peculiar species only in the Pacific flora. 



TAXODiNEiE. — Of Taxodium distichum, in the Atlantic flora; Sequoia 

 gigantea and 8. sempervirens, the Big Trees and Redwoods, in California. 



Abietine^e. — Are more numerous in North America than elsewhere. 

 Like the preceding, they prefer the sides to the center of the continent, 

 yet are not wanting to the mountains of the latter. Piniis is represent ed 

 in the Atlantic flora by twelve species; in the Rocky Mountains and 

 those of the Great Basin by six different species, not counting those of 

 Arizona ; in the Pacific flora by eleven species, four of which are in the 

 preceding flora. Larix has a single Atlantic and two Pacific species. 

 one or both of which occur in the Northern Rocky Mountains. Picea, the 

 Spruces, two in the Atlantic, two others in the Rocky Mountain, and two 

 in the Pacific flora, one of the latter a Rocky Mountain species. Tsvga, 

 one (Hemlock Spruce) in the Atlantic, and one almost the same in the 

 Pacific flora, which has also the peculiar T. Pattoniana or Williamsomi. 

 Pse udot.su ga DougUmi) of the Pacific and the Rocky Mountain flora, most 

 abundant in Oregon. Abies, the Firs or Balsam Firs, two in the At- 

 lantic, two in the Rocky Mountain, and four or five iu the Pacific flora. 

 one of them common? 



Ol C \i>aci:.e. — Being represented only by a Zamia on the peninsular 

 part Of Florida, are beyond our limit. 



The monocotyledonous orders must he more briefly dispatched. 



Pai.mk.i:. — Are represented on the Atlantic coast and north of the 



Florida peninsula by four species in two genera. Three species in two 

 genera are described in the Botany of California ; but two ol" them are 



known only beyond the United States boundary; the other belongs 



properly to the Arizonian flora. 



