274 NOTES ON THE BOTANY OF MANITOBA. 
plants growing there must, on the forest being — into 
prairie, have either radically changed their habit or been much 
decreased in numbers, even to extermination ; while cow lant 
a d t in an open = would in the course of 
time become largely increased in numbers, provided of course that 
their habits were such as to enable shes to withstand extermination 
by the action of the fires. At the present time, nothing of the 
nature of a shrub growing upon the bare open prairie as able 
to hold its own against the fire with any success, except the dwarf 
prairie rose (Rosa acicularis), the wolf willow (Eleagnus argentea), 
a — allied — of willow (Salix). Again, it can hardly 
supposed that the extermination (now practically, if not actually, 
Fae ic of an animal once so numerous on the prairies and so 
essentially characteristic of them, as the buffalo, has not had some 
_ effect uw ae the prairie flora. I shall have occasion to allude to 
'. this point again when speaking of Stipa a Astragalus caryo- 
carpus, and Sanicula Marylandica. These causes must have had 
—_ _ effect upon the penito flora; but it is cameeniak to iron 
of Nature. 
Nothing in es with the flora of the prairies piepekce 
ne 9 AB succession in which the different imei 
§ month or period. Many times over I observed some 
: previously unnoticed species bursting into flower more or less 
abundantly in the course of a few days, to be replaced somewhat 
later by another kind or other kinds, equally unobserved up to that 
time. This 4 ater! was, perhaps i 
Some extent be observed in in England, but still not vas anything like 
the Same noticeable extent jt is in Manitoba. The powerfully- 
disturbing influence of cultivation which comes into play here, but 
is as yet entirely absent from wide areas on the prairies, is un- 
_ doubtedly Fra this. ehieied: of this, indeed, is 
iat on saga seg + has been recently “broken” 
n the “fire-guards” ploughed by settlers round 
mises to aoe their ene from the fire, the disturbing 
ten is very noticeable. From such spots I was 
eclm 
often able to obtain specimens of flowers the bulk of which had 
S—some of them months—before I arrived in the 
Plants flourishing in such situations were, too, 
ee of a different species. fro se grow e un- 
prairie immedi ‘around. Achillea Millefolium, Lophan- 
» Chenopodium ers are the plants which 
ever remember seeing the last-named growing on 
