Horsetail and Club Mosses
Nature Bulletin No. 634-A March 26, 1977
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
HORSETAIL AND CLUB MOSSES
Just for fun, sometime, lie on your stomach in a patch of long grass or
weeds and remain perfectly still, but watchful. Pretend that you are a
tiny person -- like Alice in Wonderland -- lost in a jungle of towering
trees. It is easy to imagine that an ant is a terrible dinosaur, that a worm
is a huge snake, and that grasshoppers are gigantic flying dragons.
If you try that stunt in a patch of those queer flowerless plants called
Horsetails, or in a bed of the equally primitive Club Mosses, you may
get some idea of how the landscape appeared during the Coal Age, 300
million years ago.
Then this earth had a warm humid tropical climate, and vast portions of
it were swamps choked with fantastic types of luxuriant vegetation.
There were tree horsetails, 60 feet tall and almost identical -- except in
size -- with their small descendants we see today. There were treelike
club mosses, one of them attaining a height of 100 feet. There were
great seed ferns -- now extinct, tree ferns, and an understory of true
ferns among which there were some kinds of stems; one that bears
spores and another that is sterile.
One of the first signs of spring is when the tan-colored fruiting stems
appear. They grow rapidly to a height of from 6 to 12 inches. On the
stem, at each joint, there is a sheath of small pointed scale-like leaves,
black or dark brown that lie flat against it. At the tip there is a yellow
cone crowded with scales which soon open and release clouds of dust-
When a fertile stem begins to wither, the roots send up a green, jointed
sterile stem that lives until autumn. At each joint there is a whorl of
small needle-like stems, also green and jointed. It looks like a little
pine tree but when one droops downward it reminds you of a horse's
tail. Muskrats and deer are said to relish the horsetails that grow in and
around swamps but the chief of these plants is that they develop
branching nets of roots at or just beneath the surface of the ground.
They anchor the soil, preventing wind or water erosion.
Scouring Rushes, closely related to the horsetails, although very similar
in most respects, are evergreen perennials -- they live from year to year.
A common species, which grows in clumps along streams and the
borders of swamps, has dark-green jointed stems from 3 to 8 feet tall,
with longitudinal ridges. The sterile and fertile stems are alike but the
latter bear cones. They are strengthened with bands of gritty material --
fine particles of silica -- and in pioneer times were used to scour pots
Club Mosses are little evergreen plants with trailing stems from which
grow erect shoots that, on some kinds, resemble tiny trees. Covered
with moss-like leaves and reproducing from spores, they prefer cool
deep forests and are rare or extinct in this region.
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Update: June 2012