Forest Preserve District of Cook County, Illinois
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Bog Plants
Nature Bulletin No. 385-A   June 6, 1970
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

Fifty 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.

But 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 are found.

Four 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 attract.

Unless we get bogged down, the next bulletin will be issued on Sept. 12.

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