Nature Bulletin No. 385-A June 6, 1970
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
years ago there were probably more different kinds of plants
within a 50 mile radius from the Loop than anywhere else in the
Temperate Zone. Industrial, commercial and residential developments,
plus drainage and fires have erased the habitats where many of the
more uncommon kinds flourished, including almost all of the
tamarack swamps and quaking bogs.
These bogs were a heritage from the last glacier. Its front had
advanced in a great curve, from 10 to 20 miles beyond what is now the
shoreline of Lake Michigan, before the climate changed and it began
to melt back. Apparently the retreat was so rapid that huge blocks of
ice were left behind, surrounded by the outwash of boulders, gravel
and ground-up rock called "drift". These undrained depressions;
became lakes. Sphagnum moss invaded many of them and eventually
the thick floating mats of it supported a variety of bog-loving plants
including certain shrubs, tamarack, and a small species of birch. Such
lakes became bogs.
bogs change. The dark cold water beneath the mats of vegetation
is so lacking in oxygen that, as the mosses and taller plants die, little
decay takes place and they sink to the bottom where they form an ever-
increasing deposit of peat. After hundreds or thousands of years the
shallower and the older bogs became completely filled with peat.
Today, in a few of the younger deeper bogs, which so far have escaped
destruction by civilization, we may find some of the interesting plants
typical of bogs much farther north. They require the acid condition
created by the growth of sphagnum moss.
One of the most common shrubs is the Poison Sumac. It may become
from 10 to 25 feet tall, has greenish-white berries, brilliantly colored
leaflets in autumn, and is as poisonous or more so than poison ivy.
Black Alder or Winterberry, often called Northern Holly because of its
profusion of bright red berries, may also become quite tall. The
smaller shrubs include Labrador Tea, with queer woolly rolled leaves
which are aromatic and have medicinal properties; Bog Rosemary,
also having peculiar leaves; Leatherwood, which has thick leathery
leaves and prefers the open sunny places; and perhaps one or two
species of blueberries. Two kinds of cranberries and the Gray Grape
members of the orchid family, because of their beautiful and
unusual flowers, have been almost exterminated by greedy pickers and
collectors. The Grass Pink, the Stemless Ladyslipper or Moccasin
Flower, the Large Yellow Ladyslipper, and especially the Showy
Ladyslipper, grew profusely in some Chicagoland bogs. There were
two species of white violets. Some interesting plants with showy
flowers grew along the marshy borders. In the bog proper, one may
find three unique plants.
The exquisite little Goldthread has dark evergreen leaves with three
leaflets and a slender horizontal root which is bright yellow and very
bitter. It was used by Indians as a dye and for medicinal purposes. The
Pitcher Plant has a single purple or yellow flower rising on a tall stalk
from a rosette of pitcher-shaped leaves. These are usually well-fitted
with water and a sticky fluid in which drowned insects are numerous
but it is no longer believed that the plant is "Carnivorous" and lives
upon the soft parts of their bodies which it absorbs. The same is true of
the Round-leaved Sundew although its long-stalked round leaves,
which lie close to the ground, are covered with sensitive hairs that
exude droplets of sticky fluid and can bend inward to trap insects they
Unless we get bogged down, the next bulletin will be issued on Sept. 12.
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Update: June 2012