240 Part II. 
4. The Western Mountainous Elements and the Great Basi 
Black Hills Flora. The Black Hills are on the boundary line between 
South Dakota and Wyoming, the larger part Iying within the former stat 
They constitute an isolated range about 
a0 to 5o miles wide east and west. The nearest mountains are the Big Ho 
Mountains on the west and the Laramie Mountains to the southwest. 1 
highest point is Harney’s Peak 7368 feet (2245 m). The varied flora of the 
hills has been derived from several sources of supply. 
the East, from the Saskatchewan region, from the prairies and table- 
west of the Missouri River from the Rocky Mountains and west thereof. 
following trees and shrubs have come from the east and northeast. 
EEE 
Negundo aceroides Moench: (= Acer 
Negundo L.). 
Amelanchier alnifolia Nutt. 
Betula glandulosa Michx. 
» papyrifera Marsh. 
Chimaphila umbellata Michx. 
Cornus canadensis L. 
»  stolonifera Michx. 
Corylus rostrata Ait. 
Crataegus coccinea Linn. 
Fraxinus lanceolata Borkh. 
Juniperus virginiana L. 
Linnaea borealis L. 
The Rocky Mountains in the west 
Those marked with an asterisk * are found on the Pacific coast and in 
northern Rockies; those with a dagger + in the Rocky Mountains southw 
*Berberis aquifolium Pursh. 
+Betula occidentalis Hook. 
+Ceanothus ovatus Desf. 
» velutinus Doug]. 
+Cercocarpus parvifolius Nutt. 
*Juniperus nana Willd. 
Pinus ponderosa Lawson var. scopu- 
‚lorum Engelm. 
In the foot hills and the lower part of the Black Hills, the flora is essell 
ally the same as that of the surrounding plains, with an addition of 
plants that have ascended the streams. 
a northern origin. Most of the plants 
transcontinental distribution, but often characteristic of a higher latitude. ; 
only true trees of western origin, as shown in the lists above, 
The other full-sized trees are 
ponderosa and Betula occidentalis. 
Chapter 3. 
120 miles long north-northwest, and 
There are plants fr 
Ostrya virginiana Mill. 
Picea canadensis Mill. 
Populus deltoides Marsh. 
> tremuloides Michx. 
Prunus americana Marsh. 
»  pennsylvanica L. 
» virginiana L. _ 
Quercus macrocarpa Michx. 
Rhus glabra L. 
Shepherdia canadensis Nutt. 
Symphoricarpus racemosus Vväf. 
florus Robb. 
Ulmus americana L. 
have supplied the following pla 
+Populus angustifolia JameS- 
*Prunus demissa Nutt. 
*Rhus trilobata Nutt. 
+Rubus nutkanus Mocino. 
*Spiraea lucida Dougl. .r 
*Vaccinium Myrtillus L., var. M@ 
phyllum Hook. ee 
easte 
the flora iS 
In the higher parts, 
composing it are of a more Of 
are 29 
easte 
