certain weeds should be placed, and as to the position in the class ;. 
there may even be differences of opinion as to whether a plant 
should appear in a list of weeds at all or not, and this would 
demand an answer to the question, What is a weed ? The diction¬ 
ary defines the word weed as “ Any plant growing in cultivated 
ground to the injury of the crop or desired vegetation, or to the 
disfigurement of the place; an unsightly, useless, or injurious 
plant.” Then we have the old definition, “ A plant out of place,” 
which is broad enough, and at the same time has the virtue of 
brevity. There is evident propriety in including in a weed list, 
not only the decidedly injurious ones, that cause so much trouble 
in gardens and fields, but also the unsightly and useless plants 
that disfigure our road-sides, ditch-banks, pastures, and waste 
places. We must include, also, some of our most useful plants, 
because they frequently give trouble by appearing out of place. 
Alfalfa is invaluable to this Western country as a forage crop, but 
when it springs up in your strawberry bed you regard it as a weed, 
and treat it accordingly. A field of alfalfa is broken up and sown 
to wheat; the roots are imperfectly cut, and we have two crops in 
competition on the same ground—neither is profitable. It was 
wheat that was wanted, but the yield was cut short by the alfalfa ; 
in this case the alfalfa is in effect a bad weed. Many other plants 
may possess this two-faced character—useful or ornamental when 
in their proper places, but becoming noxious when appearing 
where they are not wanted. 
From observations thus far made, we have included in our 
list of weeds 228 species of plants. Regarding most of them there 
is no question—they are plainly weeds; a few, however, are placed 
in the list provisionally, and our estimate of their position may be 
changed by further observation. A considerable addition will 
undoubtedly be made when our study has been extended to in¬ 
clude the southern and western portions of the State. 
A very natural inquiry concerning weeds is, Where do they 
come from ? Ours are in great part native ; they are plants in¬ 
digenous to the foothills and plains, which, by reason of the favor¬ 
able conditions afforded them in the irrigated districts, are enabled 
to develop strongly and multiply rapidly. They are aggressive in 
the struggle for possession of the land, and thus become pestiferous 
to our cultivated crops. Sixty-five per cent, of our 228 species of 
weeds belong to this class ; the balance, or 35 per cent., are intro¬ 
duced. These foreigners are mostly European plants, which first 
secured a foothold on the Atlantic coast, and then, following civil¬ 
ization, gradually migrated westward. A few have come to us 
from the Southern States and Mexico. 
The proportion of native weeds is greater here in the West 
than it is East. In some of the New England States a majority 
