Grant County herald. [volume] (Lancaster, Wis.) 1850-1968, 1889-10-03
sox,ous WEEDS or WISCONSIN.
From Bulletin No. 90, Agricultural Experiment
Station, Madison.
THE CANADA THISTLE.
lC:rsi,l,n arnense. Scon.l

leaves, less rigid prickles and smaller
flower heads, from the common or bull
thistle, Ctrciam lGneeolatstm. No one
who has ever seen the two would have
the least trouble in distinguishing them.
II is much more to be dreaded than the
latter species. as it is far more difficult
of determination. Its rather slender
stem grows one to three feet tall and
bears numerous purple flower heads,
each OF which contains many individual
flowers. Its seeds are provided with a
very light downy pappus, by means OF
which they are very readily dissemin-
ated by the wind. The root of the
Canada thistle is perennial, that is, it
lives in the ground from year TO year,
and it sends out in all directions vigor-
Gus underground stems, or rootstocks.
1t is owing to this latter quality that il
is enabled to spread so rapidly and be-
come so difficult of determination.
These underground stems develop buds
at their joints, which grow upward
forming new plants. Thus single
plant, il undistnrbed for two or three
years, is capable of spreading over a
square rod or more of ground by means
of its rootstocks alone.
1t is also propagated to a considerable
extent by its seeds. as is attested by the
IA pidity with which it spreads down the
valleys of streams, and the frequency
with which patches of it appear about
old hay stacks and places where hay
that contained its seeds had been fod-
dered out during the winter. In New
York it has been often known TO come
up thickly |here forests have been
cleared off Prof. Bales has observed
however, that many of the flowers OF
the Canada thistle are imperfect, and
but small percentage of them pro-
duce fertile seeds. 1t may be that fewer
fertile seeds are produced in the west
ern than the eastern states. 1t is prob.
able, at all events, that the seeds actu-
ally play less important part in the
dissemination of this plant than their
apparent great number, and the extreme
facility with which they appear 10 be
carried about by the wind, would indi-
cate. 1t is not likely that its downy
dappus that we so often see floating
about in the air in August, sometimes
at great height, often bears with il a
fertile seed.
The Canada thistle is certainly one OF
the most aggressive and tenacious
weeds. Il has attracted more attention
and been the subject of more discussion
than any other weed that has ever in
vaded our country. with the possible
exception of quack-grass. Swamps and
forests are almost the only grounds I'M
der vegetation that are not liable to in
trusion by it, and when it once secures
foothold it is usually quite difficult Of
eradiction.
History. A tradition says that the
Canada thistle was introduced into Can
ada from France, by the early French
settlers. as food for swine. However
that may be. is is certain that it was
described in Europe before il was known
in the Unit ed States, and that it came
into New York and Vermont from Can
ada. The time of its first invasion Of
! these states is not known, but it appears
certrin that it was prior to the present
century, for it is on record that as early
as 1895 law was passed by the legis.
lature of Vermont directing its destruc-
ton, and similar law was passed by
the New York legislature in 1918. 1t
was mentioned in the transactions OF
the State Agricultural Society of New
York prior TO 1904, and was noted by
the Siberian botanist Pursh, at the lower
end of Lake Champlain in 1907. BY
! 1914 it had spread southwark to New
York City and eastward TO Boston. BY
1920 it had commenced to invade the
wheat growing sections of western New
York, and ten years later was a subject
of much concern there. In 1928 il
reached Chester county, Pennsylvania,
but did not spread so rapidly there as
farther north; as late as 1885, il was
not known west of the Allegheny mount
aims. Since then it has become well
distributed over the Northern states.
When it first commenced to invade the
farms of northern Vermont and New
York, the farmers were ignorant Of
methods for combating it, and the ra-
pidity with which it took possession Of
the acres that had been wrested from
the forest at such great cost excited
feelings among the settlers that were
akin TO alarm. Strange to say, how
ever some regarded it as a valuable
fodder plant, and were apprehensive
lest the law aimed at its destruction
/ NOulu Cutall tuO IOoo va q HiOaO UiCS9'
ing The knowledge of Canada thistle
warfare, so far as such knowledge
exists, vas of necessity, early developed
in the invaded districts, and it may be
truly said that the last three score years
have added remarkably little to our in
formation as TO the best means of ex-
tirpating this plant,
Hon. best destroyed. In the year 1916,
MIR. Ambrose Stevens of New York,
presented an essay before the Agricultu.
raj Society of that state, on 1.-The Elk.
tirpation of the Canada Thistle In
this essay Mr.. Stevens gives the results
of careful experiments conducted during
the years 1841 to 1S45 in the destruc-
ton of this plant, and also an abstract
of nearly every article ON the subject
that had appeared in the agricultural
olrnals and published transactions OF
the state up to 1886. summing up his
evidence in carefully drawn conclusions.
Believing that the problem of keeping
this pest in subsection will not differ
materially in Wisconsin and New York
an abstract of Mr. Stevens experiments
and his deductions therefrom are here
given, as it has seemed to the writer