British North American Plants. 13 
ing distribution. There are, however, illustrations of 
special, more or less uniform soils in the great deposits of 
black vegetable mould forming these newer Manitoba 
prairies, and possibly also in the drift deposits of the Mis- . 
- souri Coteau and other such localities, and these may be, in ~ 
connection, however, with associated ,influences, found to 
have some effects on the distribution of species in these 
sections. 
It is unnecessary to individualize this well-known group 
by a list of species. 
WESTERN PRAIRIE GROUP. 
Some species associated in range with true western 
prairie plants, appear to extend to the foothills of the 
Rockies, and even in individual cases climb the Rockies 
themselves. More information is needed with regard to the 
limits of this group. The following, however, in our present 
knowledge of their range, illustrate it :— 
Cleome integrifolia, T. & G. Potentilla fastigiata, Nutt. 
Arenaria congesta, Cham. Heuchera parviflora, Nutt. 
Malvastrum coccineum, Gray. £nothera ceespitosa, Nutt. 
Linum rigidum, Psh. (Enothera triloba, Nutt. 
Paronychia sessiliflora, Nutt. Centunculus minimus, L. 
Rhus trilobata, Nutt. Plantago pusilla, Nutt. | 
Lupinus Kingii, Watson. Heliotropium curassavicum, L. 
Astragalus kentrophyta, Gray. Polygonum imbricatum, Nutt. 
WESTERN CENTRAL GROUP. 
The distribution of the members of this group from the 
Pacific Coast or the interior of British Columbia eastward 
towards or into Manitoba, is peculiar, but will be probably 
found to follow to some extent, the lines of mean tempera- 
ture. The few species which occur in the Northern United 
States east of the Mississippi, have a general northwestward 
range. As more is known of the flora of the Saskatchewan 
and Peace River countries, the northern limits of distribu- 
tion of many of the species of this group will, I think, be 
found to nearly parallel, as some do now, the trends of 
