Nature Bulletin No. 332-A   February 15, 1969
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:MOSSES

Few sights are more restful and attractive than a moss-covered rock or 
log in a deep woods or along a secret shady stream. At close range, in a 
child's imagination, a carpet of moss is a fairy forest where the "little 
people" make magic beneath its make-believe "trees".

The word "Moss", strictly speaking, belongs to a certain definite group 
of tiny green plants, but in common usage many other small greenish 
plants are also called mosses. For example, reindeer moss is really a 
lichen. Spanish moss is a flowering plant related to the pineapple. It 
grows on trees in festoons that dangle like long gray beards. The 
"moss" on the shady side of a tree trunk is an alga, The true mosses 
grow from sea level to above the timberline on mountains, and from the 
moist tropics to the arctic tundras which are blanketed with lichens and 
mosses. In temperate regions, though not conspicuous, we find them on 
the soil of old fields, rocks, trunks of trees, and rotting logs; in moist 
woods and bogs; and even under water in swift streams. Perhaps 
because of smoke and fumes, they are seldom found in cities.

Mosses furnish no food to man and appear to have little value but they 
play, and always have played, an essential role in the colonization of 
land areas by our modern flowering plants. On the barren rocks and 
areas exposed by glaciation, lichens grew first. When they died, leaving 
a trace of organic matter, this allowed mosses to follow and, after them, 
our modern trees and flowers. Mosses are hardy. Even in midwinter the 
greenest thing you are likely to find is a bed of moss.

Of the 1000 or more species and varieties known to the experts -- and it 
takes an expert to name some of them -- there are a dozen or more that 
an amateur with a lens can find and identify in the Chicago region. All 
are built in the same general way and the Hairy Cap Moss, also called 
Pigeon Wheat, may be chosen as an example. It is a rather coarse moss, 
growing on dry open knolls near damp woodlands. In fall or winter it is 
a greenish-brown cushion of bristling stems. In early summer it is 
tipped with the vivid green of new growth on top of the old dead growth 
of previous years. At this time it also sports a forest of shining ruddy 
stiff bristles each bearing a woolly object like a small grain of wheat. 
This is covered with a pointed cap which encloses the spore capsule. 
When the spores are ripe, this cap falls off to expose a beautiful green 
four-sided "pepper box" which sifts the fine dust-like spores into every 
passing breeze.

In a damp suitable place, one of these spores sprouts and grows-into a 
sprawling network -- perhaps the size of your hand -- of green threads 
which produce knots or buds. Each of these shoots up a leafy stem held 
erect by fine root-like anchors -- the "trees" of the elfin forest. Some 
stems are topped with rosettes of leaves set in little cups which produce 
sperm cells. Melting snow or spattering raindrops carry these swimming 
sperm cells to egg cells that appear on the tips of other stems. From 
these, a new spore capsule grows and so the cycle is repeated.

Best known is the Sphagnum or peat moss which grows in bogs and 
gradually forms peat as it lives and dies. Because each pound of it can 
absorb as much as 200 times its weight of water and still remain loose, 
it is harvested on a large scale for use in nurseries, for shipping plants, 
and for making surgical dressings.

Irish moss, neither green nor a moss, is an edible seaweed used in 
puddings.