Upham.] 
156 
[May 21, 
lands, or in brackish sloughs and ponds, or on the borders of sa- 
line lakes. These include Ranunculus Cymbalaria, Pursh, Ribes 
setosum, Lindl., Grindelia squarrosa, Dunal, several species of Ar- 
temisia, Senecio palustris, Hook., Crepis runcinata, Ton*. & Gray, 
Chenopodinm glaucum, L. (indigenous), Monolepis chenopodioides, 
Moquin, Atriplex patulum, L., var. subspicatnm, Watson, A. ar- 
genteum, Nutt., and A. Nuttallii, Watson, Suseda depressa, Wat- 
son, and its var. erecta, Watson, Zygadenus elegans, Pursh, 
Triglochin palustris, L., Potamogeton marinus, L., and its var. 
Macounii, Morong, Zannichellia palustris, L., Scirpus pungens, 
Vahl., and Carex flava, L., var. viridula, Bailey. 
Introduced species. Weeds . — Nearly all of our plants naturalized 
from other countries, mostly from Europe, occur in such situations 
and conditions as to entitle themselves to be called weeds, under the 
definition given by Lindley and Moore, that a weed is “ any plant 
which obtrusively occupies cultivated or dressed ground, to the exclu- 
sion or injury of some particular crop intended to be grown.” A 
few, however, which are not commonly troublesome in fields and 
gardens, find congenial locations along roadsides and fences, on rail- 
way embankments, or in door-yards and around deserted dwellings. 
But we cannot say, conversely, that all weeds are introduced spe- 
cies ; for many of our most annoying and persistent weeds, espec- 
ially in the western region of the prairies and plains, are indigenous 
species, and some of these are rapidly extending their geographic 
range eastward. 
In the state of Minnesota, comprising 84,286 square miles, there 
are now known about 1,775 species and varieties of phsenogamous 
and vascular cryptogamous plants, of which 145 are naturalized 
and adventive species. Probably the flora of the Red river basin, 
which lies partly in Minnesota and includes, with the tributary As- 
siniboine, approximately the same area, has about the same total 
number of species and proportion of acclimated aliens. In gen- 
eral, the weeds of the two regions are identical; but some that 
have become abundant in the earliest settled portions of Minnesota 
have not yet spread to the Red river valley, or occur but rarely 
there. On the other hand, a few that are pests to the farmers of 
Winnipeg, Kildonan, and Selkirk, are unknown in the upper Mis- 
sissippi region, as about Saint Cloud and the u Twin Cities” of 
Minneapolis and St. Paul. During the future years many weeds 
that are now rare or restricted to limited areas will doubtless over- 
