Hayden.] 318 [February. 



days in saccession. The dry season commences about the middle of 

 July, and usually continues through the autumn and sometimes a 

 portion of the winter. Occasionally heavy storms of short duration 

 occur in September and October, but usually the weather is delight- 

 ful, the sky being sometimes for weeks with scarcely a cloud. Prob- 

 ably three-fourths of the plants of the country are in blossom dur- 

 ing the months of May and June and the first half of July. During 

 the month of September the ground becomes parched by drought, 

 and very little vegetation clothes the prairies, and everything pre- 

 sents the appearance of desolation ; very few flowers are in bloom, ex- 

 cept now and then a composite plant. The greater portion of the 

 Upper Missouri flora belongs to the great families of Cruciferoe, Leyu- 

 minosce, Compositce, Chenopodiacece, and Graminece. The Crypto- 

 camic plants are rare. Between Council BluSs and the foot of the 

 Rocky Mountains, there are very few ferns, mosses, lichenes, or fungi, 

 throughout what is called the prairie region. There are very few trees 

 to be seen except those which skirt the streams, and these are mostly 

 a species of cotton wood, Pupulus anjjulata. In the limestone dis- 

 trict of the State of Missouri, the sugar maple, Acer sacchariniim, oc- 

 curs in great abundance, and disappears in Kansas. The Acer ruhriim 

 continues to the mountains more or less rare. On the Vermilion and 

 Big Sioux Rivers this tree is abundant, and the Indians have made 

 suf^ar from its sap. Most of the species of oak and the hickory cease 

 in latitude 42^°. At the mouth of the Big Sioux, Tilia Americana, 

 Gymnocladus Canadetisis, Ulmus fuloa, Juglans nigra, J. cinerea, 

 Celtis occidentalis, GledUschia triacanihos, occur in small quantities; 

 and in ascending the Missouri, these trees begin to disappear, and 

 entirely cease before reaching the mouth of White River. About 

 one hundred miles above Council Bluff's, the last sycamore, Platanus 

 occidentalis, is seen along the Missouri. It has not been observed 

 west of that point. Negiuido accroides Frnxinus Americana, Quercus 

 macrocarjKi, two species of Juniperus, and certain under shrubs, as 

 Xanthoxj/lum Americaniim, Stajjhj/ha trifoliata, Eaoni/mus atro- 

 purpureus, tSi/mphoricarjyus vu/tjaris, Cornus sericea, 0. stoluni/era, 

 several species of Vi/is, Ribes, Rhus, Rosa, and Salix, are found more 

 or less abundant to the foot of the mountains, especially along the 

 bottoms of the Missouri or Yellowstone. Among the shrubs bearing 

 palatable fruit, are Shepherd ia aryentea, Amelanchier Canadensis, 

 and Frunns Virginiana, which are universally distributed, and of 

 great value to the wandering Indians. 



Much might be said in regard to the geographical distribution of 



