SECTION IV., 1882. Paiste | 
V.— Notes on the distribution of Northern, Southern, and Saline Plants in Canada. 
By Joux Macoun, M.A., F.L.S8. 
(Read May 25, 1882.) 
Having received instructions last January from Dr. Selwyn, Director of the Geological 
and Natural History Survey, to prepare a catalogue of all the known plants of the Dominion 
with special reference to their distribution, I proceeded to do so and up to the end of the 
musci have catalogued 3,220 species. My time having been limited, I have not been able 
to complete the work, but I have specimens of the remaining order which will raise the 
list to about 4,000 species. No species is included in the list of which we have not an 
authentic record and at least 95 per cent. are represented in the Geological Museum. 
The object of the present paper is to lay a few of the apparent results of this work 
before the section and ask criticism on the statements and deductions I may make. 
British Columbia, owing to its peculiar topographical features, has a peculiar flora. In 
the humid atmosphere of the coast we find many Asiatic and Californian forms and it is 
no unusual occurrence to find the same form at intervals along a coast line of 1,500 miles. 
Ranunculus Californicus is just as common around Victoria as it is at San Francisco, and 
the same species has been detected by Dr. G. M. Dawson on the Queen Charlotte’s Islands. 
Eastward of the Coast Range is the interior plateau of British Columbia, which is a 
continuation of the arid country that extends from Arizona northward to lat. 53°. Within 
this area many very interesting species have been found, which are peculiar to dry and 
arid regions and which are supposed to be peculiar to southern localities. In the south 
these species live and thrive where frost is unknown and yet I have gathered them where 
the thermometer often sinks to 20° below zero. I have noticed the same on the southern 
prairie where many species that find a home in California and Arizona appear in profusion 
and often in close proximity to species that cross the Arctic Circle. It is evident from the 
distribution of the various species that certain forms require a dry atmosphere and arid 
soil during their period of growth and, if they obtain these, it matters little whether during 
the period of rest they are subjected to intense heat or extreme cold. As an illustration of 
this fact I may state that Opuntia Missouriensis grows in abundance and ripens its seeds 
on the north bank of the Peace River in lat. 56° at Dunvegan and at this point the winter 
temperature is often 55° below zero. I might multiply instances to illustrate this point 
but refrain, as my desire is to call attention to my previous remark that certain plants 
require well drained soil and a dry atmosphere. These we name southern forms. Others 
again we call boreal because they generally find their home in the north; and yet these 
boreal species are found far to the south of their usual habitats if the conditions in which 
they are growing are suited to their wants. 
Empetrum nigrum, 
Comandra livida, 
Rubus arcticus, 
and many others are of this character and, when we find southern species so called and 
