On Plants of the North-West. 5% 
TRIANDRIA. 
Monoeynia. 
Pedia radiata Mz. 
Paleriana radiata Willd. Gross Isle, May 22d. 
V.locusta [radiata L. Sp. pl. 
Iris lacustris Nutt. Gen. 1. p. 23. Scape five to six 
inches high, about the length of the leaves. Radical leaves 
eusiform, one fourth of aninch broad. Mr. Nuttall discove- 
red this Iris in the same place where it was found by Capt. 
Douglass—on the ay shores of the Islands of Lake 
Huron. 
Sisyrinchium mucronatum Me. Pluk. Phytorg. t. 61. f. 1. 
Gross Isle, May 21. - 
Explanatory letter from Prof. Douglass to the Editar, dated New-York 
Aug. 22, 1821. 
Dear Sir, 
I must beg leave to observe, in the first place that the collection of plants 
was made by a person, who, besides not being a professed botanist, was al- 
most constantly engaged with other objects of research. The formation of 
an Herbarium, requiring much leisure and frequent attention, could 
scarcely be expected, under such circumstances, and would not have been 
undertaken, except in the exigency of having no professed botanist attached 
to the Expedition. Secondly, the region of country traversed by the Ex- 
pedition, particularly that bordering upon Lake Superior and the upper 
Mississippi, as well as a considerable portion of that on the Ouisconsin and 
Fox Rivers and around Lake Michigan, is but indifferently rich in plants at 
best, and this collection is besides chiefly confined to such as flower in the 
course of the summer months. ‘The deficiency I have endeavoured to sup- 
ply as far as possible by notes, particularly on ithe forest growth, which [ 
have interspersed in my journal; these however being at West Point, it is 
at present out of my power to communicate them. : 
Finally, a part of the collection was imjured by an accident on the Ouis- 
consin, in which my canoe was very nearly filled with water before it could 
be got ashore. The consequence of which was that nearly all the plants in 
one case were completely spoiled before I was able to dry them. Such as 
the collection is, however, the catalogue is entirely at your service, and I 
am glad that so much interest has been given to it by Dr. Torrey. The wvt- 
laria perfoliata of this catalogue is the plant which I mentioned to you some 
time since, as efficacious in the cure of the Rattle-snake bite—Of this I have, 
been witness, but the efficacy of the Pedicularis Canadensis for the same 
purpose, I can only state from report. 
I remain, dear Sir, your friend 
and humble Servant, 
D. B. DOUGLASS. 
Vou. IV.....No. ¥. 8 
