MIDLAND NATURALIST. IOI 
as Aster and Solidago. Everything has seemed rather notably dif- 
ferent from what would be specifically the same thing if it had 
come from the farther East, or the remoter West, or even from the 
prairies of Wisconsin, or Iowa or Minnesota. 
Not very long since I asked of my friend Dr. J. Lunell, for 
some time a resident of this interesting region, that he would send 
me specimens of such Thalictrum species as he had collected in 
North Dakota. Of the specimens which he kindly and promptly 
sent,there are two which represent species hitherto undescribed; and 
I more than willingly present herewith my determinations of them 
all. And when I say more than willingly, I imply that it may be, and 
ought to be, more than a pleasure to investigate critically any part 
of any floral district standing thus by geographic limitations aloof 
from several others, and nothing less than the duty with him who 
has done so, to make known in how far, and in what manner of 
specific or varietal departures from more familiar types the mem- 
bership of each well known genus then presents itself. 
THALICTRUM DIOICUM Linn. Under his number 79, Dr. Lunell 
sends two beautifully prepared specimens from ‘“Thickets, Penin- 
sula of Lake Ibsen, Benson County, r3 June, 1909." I assume 
that some one of Dr. Lunell's correspondents has referred these 
specimens to 7. occidentale for thisis the name written on the label, 
The two specimens belong to different species, and neither is 7. 
occidentale. A small plant, not yet in flower, or even in well develop- 
ed bud at the date, is plainly 7. dioícum. Its height is only a foot. 
Its leaves are two only, and both arising from the lower part of the 
stem. The leaflets are ample and very thin. They are much broad- 
er than long, of a semiorbicular outline, and are beautifully and 
doubly crenate-lobed, all the secondary lobes being equal and very 
obtuse. These are precisely the marks by which anyone conver- 
sant with vegetative characters in this genus recognizes T. dioicum 
when not in fruit. I speak of the species in its broader sense; for 
this Dakota plant, when its fruit becomes known, might easily prove 
more or less distinct from the East Canadian type of T. divicum. 
Now the second specimen before me under Dr, Lunell’s num- 
ber 79, is not at all the same plant as the other. It is in full flower, 
or even a little past that stage, at the moment when the other is 
hardly yet showing its buds. It is much larger, also has numerous 
leaves up and down its stem, and in the pattern of its leaflets it is 
altogether diverse from T. dioicum. What it is we shall not be like- 
