THE MISSOURI AND PLATTE RIVERS, ETC. 17 
Respecting the climate and eae eo irthaa of plants, 
much might be said in this connexion. nere is in this country a 
wet and a dry season, The wet season usually commences about the 
middle of March, and continues until the middle of May. The rains 
during this time are frequent and severe. It has been ces to rain 
thirty days in succession. The dry season commences about the ba 
dle of Ju ly, and usually Sentinal through the autumn, and so 
times a portion of the winter. Perhaps s three-fourths of the = a of 
the country are in blossom during the mouths of May and June, or 
the first half of July. During the month of September the ground 
comes parched by drought, and very little vegetation clothes the 
prairies, ja everything has the aspect of desolation. ery few flowers 
are in , except now and then a composite plant. The principal 
portion of, the flora of the upper Missouri belongs to the great fami- 
lies of Crucifere, Leguminose, Composite, “ Chenopodiacece, and 
Graminee. Of Cryptogamic plants there is a great dearth. I found 
but two species of Ferns above Council Bluffs; very few Mosses, Lichens 
and Fungi. Throughout the limestone region of the State of Missouri, 
we have the sugar maple { Acer Sacharinum] i in great abundance, also 
many species of oaks and hickory. These cease A latitude 423°. At 
the mouth of Big Sioux we find Fraxinus Americana, Fraxinus quad- 
rangulata, Tilia, Americana, quite abun dunt. Gymnocladus Cana- 
densis, sixty feet in height. Populus Cap dene:®, the most abundant 
tree in upper Missouri. Ulmus fulva, common, associated with Jug- 
lans nigra, Juglans cinerea, Celtis oviclend ii Gleditschia tricanthos, 
Acer rubrum, from which the Indians formerly made sugar on the Big 
Sioux and Vermilion rivers, two or three species of 0: c. Among 
the under shrubs may be Pneitianed the bullberry, She herdia argentea, 
which commences its growth at this point. Spe ap the borders 
Geter of species. At the mouth of Running Water, latitude ite 30, 
any of these trees and abiuhe cease, and we have from A. ae 
mountains very few forest hee the mh me agent mus 
mences in the Tertiary beds, near Fort Clark, and often covers the 
arid hi hills in that formation as with a carpet. I saw it in one locality 
in White river valley, on the top of Eagle Nest butte. On the high 
mes es of the Running Water, White river, Black Hills, on the Yellow- 
stone, and on the Missouri, above Fort Union, a species of pine is 
quite abundant—Pinus brachyptera. In the Bad Lands of ee ‘udith, 
- a second eae of that family occurs, and it is the only locality where 
- [have seen it—Abi i ae, ice About fifty miles below Fort Pierre, 
&. ‘remarkable saline Be ad t makes its appears! tig A 
t discovered by Sepaiibe Maximilian, in 
country i in 1832. It elon to the family Ch 
