Nature Bulletin No. 35    October 6, 1945
Forest Preserve District of Cook County
Clayton F, Smith, President
Roberts Mann, Superintendent of Conservation

****:SEED DISPERSAL

Plants have various ways of spreading their seeds.

Some have "fly-away" seeds. Included are the dandelion, thistle, 
tumbleweed, cattail, clematis, and many trees. The cottonwood, 
sycamore, aspen, linden, ailanthus, maple, box elder, birch and the 
pines are all trees having seeds with wings or with "down", that are 
carried by winds.

Certain aquatic plants have seeds that sink to bury themselves in.the 
mud beneath the water. Others have seeds that float and are distributed 
by the winds and currents that carry them away.

Many plants "shoot" their seeds, the seed pods popping open with 
sufficient force to throw the seeds many feet away, Notable in this 
group are knotgrass, lady slippers, violets, vetches, jewel weed, witch-
hazel, and Heavea, the Para rubber tree, The witch-hazel may shoot its 
seeds 30 or 40 feet.

The seeds of edible fruits and berries are widely distributed by birds 
and animals that eat but do not digest them. The acorns of oak trees, 
and the nuts of the walnut, pecan and hickories, are planted by the 
squirrels that bury them for winter food.

And then there are many plants whose seed are contained in burs that 
cling to the hair or fur of animals and the clothes of humans. The plants 
of this nature, common in this Chicago region, are the burdock, the 
cocklebur, the Spanish needle, the tick trefoil, the bedstraw, stick-tight, 
beggar's lice, and the sandbar.

Some of these burs are known by various uncomplimentary local 
names. Anyone walking through the fields and woodlands these fall 
days will do well to wear smooth, hard-textured clothing to which these 
burs and seeds will not stick. An Englishman of our acquaintance, who 
insisted on walking through the woods clad in rough tweeds, after 
several hours of futile effort, finally burnt the suit swearing at " a 
beastly country where such things grow".

Apparently they do not have them in England.