32 BULLETIN UNITED STATES GEOLOGICAL SURVEY. \Yol.Yl. 



II \ terk 'ace.e. — Represented by three genera, of which the two 

 small ones, Ascyrum and Elodes, are peculiar to the Atlantic flora 

 (excepl European relatives of the latter), which is rich in endemic 

 species of Hypericum) the Pacific flora has three or four endemic sp< 

 of the latter, the intervening region nothing of the order. 



Tkknstimkmiacej;. — This Eastern American and Eastern Asian order 

 is represented only east of the Alleghanies, and by Stuartia, two species 

 (the third iii Japan); Qordonia, two species, and several hardly genuine 

 species in tropical Asia. 



MALVAOE.E. — This is one of the great and cosmopolitan orders, of 

 which North America possesses a fair but not excessive representation. 

 The species and forms here increase in number south west ward. Indige- 

 nous plants only being regarded, no genus is common to North America 

 and Europe excepting Lavatera, represented by two or three singular 

 and mostly shrubby species of the Calif oruian coast. Xapcca is strictly 

 peculiar to the Atlantic flora, as also is the unique Sida Napcea. Qallir- 

 rhoe is peculiar to the borders of the same district and the plains adja- 

 cent. Sidalcea is peculiar to the Rocky Mountain and Californian floras. 

 Ingenhouzia (which is TJmrberia) belongs the Western Arizonian flora. 

 Mdhastrvm and Sphceralcca (too near generically) are numerous in spe- 

 cies on the plains and through the valleys of the Rocky Mountain region. 

 Kosteletekya is represented on the Atlantic coast, but most of the species 

 are Mexican. 



Bombace^:. — Fremontia Californica belongs wholly to the forest dis- 

 trict of the Sierra Nevada, and its only relative is Cheirostemon, the 

 Hand-flower of Mexico. 



Tiliace^e. — Excepting one or two outlying plants on the southern 

 borders, this order is represented only by the genus THUa, in two species 

 of the Atlantic States, which hardly cross the Mississippi. 



LiNACEiE. — Three or four Atlantic species of Linum, as many more on 

 the plains or Rocky Mountains, one species from the plains to the Pa- 

 cific coast, and the same is an Old World species, or nearly so: and. 

 moreover, in California and Oregon an unique group of seven species 

 (IIis/Hfoliitoii), in which the carpels are reduced from five to three. 01 

 even two. 



Z\ GOPHYLLAOEJS. — Leaving out the species of Tribulus or Kallstrce- 



miii and the Texano-Ari/onian representatives, among whicli Fagonia 

 Californica should be ranked, notwithstanding the specific name, only 

 the Creosote Bush remains, Larrea Mexicana^s shrub of the Mexican 



plateau, whicli has passed into or near the southern border of our belt 

 all along from Texas to California. 



( ir.KAM \< IB .1:. — 111 the restricted sense, are few in North America, 



consisting only of a few species of€teranium; the eastern and western 



perennial ones different ; a biennial species of a weedy character is scat- 

 tered over the continent. 



Limn wrii r..i:. — Are exclusively North American ; Limnanthes, of two 



