While not often given more than a passing glance by the average
person who sees them in nature, to the student of plant sciences the
mosses occupy a position of considerable importance. The ecologist, who
studies plant relationships, regards mosses as one of the true pioneers
of the plant world in so far as they are among the first plants to move
in on bare rock slopes and there start the process of rock
disintegration and soil making. Mosses are numerous and are therefore
regarded as important by the men who classify plants.
Perhaps no plant name has been popularly more misused than the word
"moss". Certain sea weeds are called sea mosses but no true moss is
found in salt water. In the South the "Spanish Moss" which drapes trees
and telegraph poles is not a moss but a true flowering plant. The group
of plants most commonly confused with mosses is the lichens, those
interesting associations of algae and fungi. "Reindeer Moss" which forms
such an important item on the menu of the reindeer is a lichen with
hollow stems. In Mt. Rainier National Park we have an abundant gray
"moss" hanging from trees but this is again not a moss, merely another
lichen.
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Fig. 1. FEATHER MOSS. (Hylocomium loreum) x1 |
After hearing of all of these "mosses" which are not mosses anyone
who is not a bryologist might be led to believe that mosses are limited
as to their numbers. A bryologist, incidentally, studies not only mosses
but a related group known as liverworts. Mosses, however, are limited
neither as to numbers nor as to range for the rock mosses such as
Andreaea and Grimmia are found on the bare, dry mountain tops, while
Sphagnum grows in swamps and Fontinalis, the water moss, in running
streams. In somewhat intermediate habitats, in the shade of our giant
forest trees, we find an abundance of mosses covering rocks, soil,
fallen logs and tree trunks. No region is better adapted to mosses and
it is the opinion of the writer that the moss flora of this region, when
worked out, will prove to be one of the richest in the world.
Mosses, in common with ferns, are spore-producing plants. These
spores, which are propagative units performing the same function as the
seeds of the higher plants, are borne in a container known as a
capsule which in turn is at the end of a slender stalk, the
seta. In most mosses a row of teeth line the opening of the
capsule. The nature of these rows of teeth, the peristome is of
great importance in identifying mosses.
The drawings show four of the common mosses found here. These mosses
may be considered somewhat representative of those occupying the moist
habitats of our forests with fallen trees and moist rocks abundant.
The Mniums, together with a closely related genus, Bryum, are
characterizeded by having leaves which are transparent and this makes
their identification reasonably easy for the beginner. The drawing (Fig.
4.) shows Drummonds Mnium, further characterized by having capsules in
clusters of two or three.
Fig. 2. COMMON HAIR CAP MOSS. (Polytrichum commune) x1 |
Fig. 3. THE FUSCOUS DICRANUM. (Dicranum fuscescens) x2 |
One cannot walk far into our forests without making the acquaintance
of the Hylocomiums, which are better known as the Feather Mosses. These
mosses cover fallen limbs and are among our largest. While the capsules
of Mnium are found at the end of the stem (acrocarpous) you will note
that those of Hylocomium (Fig. 1.) are on short branches along the stem
(pleurocarpous condition).
Another moss group which has an easy detail for recognition is that
of the Dicranums. In these mosses the capsule has a beak-like covering
which makes the mature capsule look like a bird's head with a long beak
protruding. The Fuscous Dicranum (Fig. 3.) is one of our commonest
mosses in the vicinity of Longmire, and covers logs and tree trunks with
a thick mat-like growth.
The last moss shown is one so common that it requires nothing more
than a few passing remarks, for all of us are familiar with the
Polytrichums, or Hair Cap Mosses, or perhaps have also known then as
"Pigeon Wheat" Mosses. The common Hair Cap (Fig. 2.) thickly covers the
soil in open places. When the long setae with the prominent "hair caps"
appear, these growths present a striking picture which attracts the
attention of visitors walking along the Trail of the Shadows. Even the
novice quickly detects the origin of the name Hair Cap, applied because
of the hairy hood which closely covers the capsule.
E. T. Bodenberg,
Ranger-naturalist.
Fig. 4.
DRUMMOND'S MNIUM x2.
(Mnium
drummondii)