Colorado Weeds. 
By Charles S. Crandall. 
It is not our present purpose to attempt an exhaustive treat¬ 
ment of the weeds of the State, but by a few brief general consid¬ 
erations, and the mention of a limited number of well-known 
offenders, to bring the subject to the attention of the farmers, in 
the hope that .they will aid us in the collection of data from which 
to compile a complete report. Our own observations have thus far 
been confined to a limited, territory. We . need detailed informa¬ 
tion from all portions of the State before we can properly classify 
our weeds, or draw correct conclusions regarding their distribution, 
and relative noxious -qualities. Hence, for the State as a whole, 
our statements can only be general. 
Every cultivated district has its weeds, and in most districts 
they are present in great variety; but the prevalent forms of one 
district may be widely different from those of another. The region 
adjacent to the eastern foothills is infested with one series of weeds 
north of the Divide, and by a greatly different series south of the 
Divide. The weeds of the plains of the eastern counties are 
mostly different from .those near the foothills, and west, of the 
range we find a class of weeds different from those prevailing on 
this side. 
A plant may be present in two or more districts, but attract 
notice as a weed only in one ; it may even be a very bad weed in 
one district and harmless in another. Thus our common Ther¬ 
mopus (Thermopsis montana ) is xeported as a persistent weed in the 
San Luis valley, taking possession of moist pasture lands, and 
gradually extending its area to the detriment of the grasses; while 
here we would class it as one of the most indifferent weeds—exist¬ 
ing, but not spreading to any injurious extent. A few kinds, are 
everywhere present, and are universally classed as injurious. 
Owing to this diversity in the weeds of different regions, and to 
the various ratings that may be given particular species in the dif¬ 
ferent districts, it is difficult to form a classification based upon 
relative badness. Adopting the commonly used division into, worst, 
bad and indifferent, it is plain that conflict would arise in any 
attempt to adjust a list to all districts ; even in a particular dis¬ 
trict there would be differences of opinion as to the class in which 
