PREFACE, 
The collection of plants submitied to me for examination, setugha/sindosiatladiigglidtaadl 
circumstances, is a very interesting contribution to North American botany. From thé mouth of 
the Kansas river to the ‘* Red Buttes,” on the North fork of the Platte, the transportation was 
effected in carts; but from:that place to and from the mountains, the explorations were made on 
horseback, and by such rapid movements, (which were necessary, in order to accomplish the objeets 
ee ae drying botanical speei- 
Indians, 
Hae oe To give some general idea of the sinlens explored by Lieutenant 
Frémont, I recapitulate, from his repoit, a brief sketch of his route. Piseapediieg Et thadabutest 
the Kansas on the 10th of June, 1842; and, proceeding up that river al 
continued its course generally along the «* bottoms” of the Kansas tributaries, but 
over the upper prairies. The soil of the river bottoms is always rich, and generally well timbered ; 
though the whole region is what is called a prairie country. The upper prairies immense 
deposite of sand and gravel, covered with a good, and, very generally, a rich soil. aint the road, 
on reaching the little stream called Sandy creek, (a tributary of the Kansas,) the soil became more 
sandy. ‘The rock formations of this region are limestone and sandstone. The amorpha canescens 
was the characteristic plant ; it being in many places as abundant as the grass. 
Cm, biltie 
Crossing over from the waters of the Kansas, Lieutenant Frémont arrived at the Great Platte, 
two hundred and ten miles from its junction with the ae: The valley of this river, from its 
mouth to the great fork be dt dred and fifteen miles long. It 
iar vidle; neti titebaeeds snk copmab-nishkbecddentintein: ‘Tegan Seirsesentiodazandedewedl 
asters, were here conspicuous features of the vegetation. I was pleased to recognise, among the 
specimens collected near the forks, the fine large-flowered asclepias, that I described many years 
ago-in my account of James’s Rocky Mountain Plants, under the name of A. speciosa, and which 
Mr. Geyer also found in Nicollet’s expedition. It seems to be the plant —— described and 
figured by Sir W. Hooker, under the name of A. Douglasii. On. the Lower Platte; and-all the 
-way to the Sweet Water, the showy cleome inéegrifolia oceurred in sie te From the Forks 
to Laramie river, a distance of about two hundred. miles, the country may be called a sandy one. 
The valley of the North fork is without timber ; but the grasses are fine, and the herbaceous plants 
abundant. On the return of the expedition Lim mi Reptember, ideuienent Rpimnnt soys the whole 
eountry resembled a vast garden ; but th 
poe eng Dotuiam, the sani: Salles livia Platte, fom the junto, as hgh wp as Laramie 
the formation consisted sandstone. 
the 
and then occurred: at intervals to the Sweet: Water river. ‘Following up the North fork, Lieutenant 
Frémont.arrived at the mouth of the Sweet Water river, one of the head waters of the Platte. 
aie” fi ck to tl pe the soil is generally y sandy, The rocks consist. of limestone, 
andstones, i eeaeememans eater) vik eng shine 
