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Herbarium — Part 5

There are many places all through the Adirondacks which illustrate the same thing in different stages of completion--Connery Pond, Mud Pond, Calamity Pond, Hidden Swamp and Averyville Swamp are examples, all within walking distance of Lake Placid, New York.

Mr. Charles H. Peck tells of an example within fifteen miles of Albany. He says:

"A marsh covered with Sphagnum, in my boyhood days, was so soft and yielding that it seemed dangerous to go over some places. It was then productive of cranberries in nearly all parts. Now it is firm in nearly all parts. The cranberry vines have almost disappeared and shrubs and young trees have come up. It is greatly changed. The same sluggish stream flows through the centre; nothing has been done toward draining it, but the mosses, growing at their summits and decaying at their base, have gradually made more dense the soft ooze beneath, till now there is sufficient soil to support sedges, marsh-shrubs and even young trees of tamarack, balsam, and spruce."

The climbing bogs may be found on the east shores of Maine, near the Bay of Fundy, in New Hampshire, Michigan, and Minnesota. They are rare in the United States on account of the short hot summers, and for the same reason, when they do occur, they do not climb declivities of more than 2deg.. In northern Europe, on the other hand, they climb declivities of 5deg. and a bog often rises a score of feet above the water in which it stands.

Peat bogs represent the accumulated remains of thousands of generations of plants, among which were the Sphagnum mosses. There is conclusive evidence that the Sphagnum mosses are an important constituent of peat-bogs now forming; and there is every reason to believe that in ages gone by they served as soilmakers for more complex peat-producing plants. Extensive peat-bogs occur in the northern parts of the world, New England, Ireland, India, and northern Europe, where the peat is used as fuel to a limited extent.

Owing to a peculiar odour given off from burning peat, as well as to other contingencies, it is not popular as a fuel. Its great value lies in the fact that, when bogs are properly drained, they afford the most desirable land for farming purposes. One-fifth of the most fertile fields in Great Britain and Ireland have been won from bog districts by draining. During the time of the Saxon kingdoms, England was to a great extent occupied by morasses which have since been cleared away. Sites of ancient bogs in northern Germany and in the valley of the River Po, Italy, are indicated by the great and persistent fertility of the soil. Probably not far from one-twentieth of the tillable land in Europe was inundated and unfit for agriculture in the eighth century.

(Genus SPHAGNUM)

Peat-mosses are common, growing in more or less compact green or purple patches on the surface of bogs, or along mountain springs and rivulets, or even floating on water. The genus is an easy one to recognise and the plants form an attractive feature of one's walk through woods or over fen-land.

The name Sphagnum (Greek ) was used by the ancient botanists Theophrastus, Dioscorides, and Pliny to indicate certain non-flowering plants. The name was restricted to a more limited use in 1719 by Johann Dillenius, a German, who was the first professor of botany at Oxford.

The plants are soft and weak-stemmed mosses, generally of large size, white or yellow, light green or sometimes red. The stems appear almost simple with clusters of branches at the summit and on the sides; the branches at the summit are grouped to form a dense rosette (capitulum), while each side cluster (fascicle) consists of from 2 to 7 or more branches, some spreading and some appressed to the stem. A cross section of the stem shows three zones of cells--the outer (cortex) of large loose cells, the central of pithy cells and the intermediate of woody cells.

The leaves are translucent, without veins, and consist of a single layer of two kinds of cells: (1) Large colourless and transparent cells (utricles), generally perforated and lined with spiral or circular thickenings (fibrils) to secure them against collapse. They have lost the cell-contents which were present in a younger stage and are, when dry, filled with air. (2) Smaller cells (ducts), containing active cell-contents and leaf-green. They are narrowly linear and form a net of rhomboidal or hexagonal meshes around the large cells. The stem-leaves are distant. Obliquely inserted, erect or bent downward, flat or concave, tongue-shaped, oval, inserted at the small or large end generally obtuse. The branch-leaves are smaller, round, oval or lance-like, concave or rolled-up lengthwise. Each leaf apex overlaps the base of the next leaf above and every fifth leaf lies in a perpendicular line on the stem, directly over the first leaf counted, that is they are five ranked.