Nature Notes

Mount Rainier National Park

Vol. XIV September - 1936 No. 3

Issued quarterly by the Naturalist Department of Mount Rainier National Park. Material contained herein may be used freely provided that credit is given to this pamphlet and the author.
C. Frank Brockman
Park Naturalist
O. A. Tomlinson

Some Common Mosses of Mt. Rainier National Park

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.

Feather Moss Fig. 1.
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.

Common Hair Cap Moss
Fig. 2.
commune) x1
The Fuscous Dicranum
Fig. 3.
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,

Drummond's Mnium
Fig. 4.

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