46 BULLETIN UNITED STATES GEOLOGICAL SURVEY. [VolTl. 



are wholly Atlantic and one is divided (ApJiyllon), the Pacific species 

 are more than twice the number of the Atlantic. 



Lentebulaoe^. — Both Utricula/Ha and Pinguicula are of good num- 

 ber and diversity in the Atlantic flora, are nearly absent from the Rocky 

 Mountain flora, and are very few on the Pacific side. 



r.icxoxiACE^E. — For a mainly tropical order, are pretty well repre- 

 sented in the Atlantic flora by four species belonging to three genera 

 (and the most distinct genus, Catalpa, also in Japan and Northern China), 

 but would be wholly absent from the western floras except for a Mexican 

 shrub {Chilopsis) which reaches the southern borders of the Great 

 Basin. 



Pedaliace^e. — Are sparingly represented in the Texano-Arizonian 

 region, but probably are not indigenous to the north of it. 



Acanthaceje. — An immense tropical and subtropical order, but prob- 

 ably without a single representative in the Rocky Mountain or Pacific 

 floras within our limits, yet with several in the Texano-Arizonian district. 

 But the Atlantic flora has an Elytraria and Hygropkila, one or two 

 species of Cellophanes, as many of Ruellia and of Dianthera, a Dicliptera, 

 and a plant of a peculiar genus, Gatesia. 



Yerbenaceje. — Of the eleven genera enumerated in the flora of 

 North America, only four are of such northern range as to come within 

 our limits. Verbena and Lippia enter into all three floras. Callicarpa 

 and Phrijma are restricted to the Atlantic flora and to a solitary species. 

 Both the latter are Eastern Asian, the Phryma in the same species. 



Labiate. — A large and important order, but after excluding the 

 naturalized plants and those which range south of the present survey, 

 neither the American species nor the genera are particularly numerous, 

 nor is their distribution such as to call for much remark. They are 

 most conspicuous in the Pacific forest in the Rocky Mountain region, 

 most diversified in genera in the Atlantic States. Of the Xorth Ameri- 

 can types, Physostcgia, Lophanthus, Pyenanthennm. and Triehostrma are 

 common to both sides of the continent, the latter most largely on the Pa- 

 cific; the latter numerously on the Atlantic side, with a single Californian 

 species far away from its congeners. The peculiar Atlantic genera are 

 Tsanthus, Cunila, Collinsonia, Conradina, Ceranthera, Blephilia, Monarda 

 (which extends into the Rocky Mountains), Brazoria, Macbridea, Synan- 

 dra. The Pacific peculiar genera are only Monardella, Pogogyne, Acan- 

 thomintha, Audibertia, the first and the last extending eastward to the 

 Rocky Mountains in single species, ITedeoma is a remaining character- 

 istic genus, with headquarters in the Texano-Mexican district, extending 

 over the eastern plains, and one species to the Atlantic. The great 

 genus Salvia \s meager on both sides of the continent, almost absent 

 from the interior, except on the eastern plains toward the south, but 

 fairly numerous in species throughout the Texano-Arizonian region. 



IM.w i \<;in LOEJB. — Are tew in species. Plantago Patagonica, which 

 abounds on the plains and on the Pacific coast southward, is very poly- 



