The Southern farm gazette. (Starkville, Miss.) 1895-1909, 1902-06-01
HOW WEEDS MIGRATE.
They Earn Their Right to
Live by the Most Har-
DIV Efforts.

How they migrate has been
plainly shown in the case of
every kind of weed extant in the
United States. Some travel ex-
ceedinglv slow by means of run
ners, or slend radiatlng branch
es, which reach anywhere from
ten inches to ten feet along the
ground and produce plantlets at
the ends, which take root and
grow. Others progress by
spreading underground, work
ing too deep to be disturbed by
either grazing stock or rowing
machines. Still others finding
the battle for life difficnlt, devel-
op strange qualities. Prof. A.
n. Prentiss. of Cornell university
has demonstrated by experiment
that a Canada thistle root. cut
into pieces one-fourtn of an inch
long, can produce shoots from
nearly every piece. So when the
share OF the plow digs down to
cut and tear this inha bitant from
it's home it more often aids in it's
further distribution.
Zone of the most interesting
yet least known methods by
which plants travel short dis
tances is by throwing their seed.
When the pods of common tare
are mature they dry in such
manner as to produce strong
oblique tension on the two sides
of the pod. These finally split
apart and curl spirally, with such
a sudden movement upward as
to hurl the peas several feet.
Many others progress in the
same way, the common spurge
and Mood sorrel in partic ular.
MANY weed seeds have spec
ial adaptives that enab bic them to
to take advantage of the wind or
float light on water. Dandelion
prickly lettuce, Canada thistle,
horseweed, milkweed and many
others equip their seed with
some feathery or winglike appa-
ratus that enables them to sail.
Ordinarily the distance this
equipment can carry is two miles
but high wind or hurricane
would bear them ten OF. fifteen.
Yet with two exceptions, the
most rapidly migrating weeds
have not travelled in this way.
Frozen ground or snow is another
great aid to the hardy migrating
weed because seeds are blown
along for great distances. But
tonWeed, giant ragweed and
barnyard grass all progress Il
that way, because thei SC, d :,
are produced late in tic rason,
and many of them are held with
such tenacity that they are dis
lodged only by the stro' est
winds, when the condition ire
favorable tor distant iourn, IS.
BY that time the ground is u-u-
ally frozen or covered with snow
and the seeds skip merrily along
before every stray gust. This
meth ID of seed dispertion is now
known to account IN part for the
general presence of ragweed,
mayweed and others along our
country roads. 1t also SHOWS
that weeds are distributed much
more rapidly over fields left bare
during the winter than those GOV.
cred with some crop that will
catch the rolling seeds. Prof.
Bailey, of the Fargo N. d. J agri-
cultural college found by expert
ment that wheat grains drifted
over the snow on level field
at the rate of 500 a minute, with
the wind blowing IS miles an
hour. Lighter or triangular grains
were found to drift much more
rapidly.
Some weeds migrate by tum-
bling. the whole plant, seed and
all, whitening into a sort of a ball
and rolling before the wind.
such are best developed in the