Home › Volumes › Mosses and Lichens › Herbarium

Herbarium — Part 13

Veil (calyptra).--Split on the side.

Spore case.--Cylindrical, brown, arched like a bow.

Pedicel.--Red.

Lid (operculum).--Long and conical.

Teeth (peristome).--The lower half tubular and pale, the teeth red.

Annulus.--Double.

Spores.--Mature in spring.

Distribution.--Headquarters in the Mediterranean basin; rare in England, common in the western states of North America.

Tortula ruralis.

Tortula ruralis is much like the preceeding, but smaller, with flowers dioicous. It grows on thatched roofs or stony ground, in tall cushions 1 to 3 inches deep; bright green above and bright red-brown below. The awn at the apex of the leaf is strongly spiny, transparent above and often red at the base, sometimes equalling the rest of the leaf. The spore cases are narrowly cylindrical with a lid half as long and a stout red pedicel about an inch long.

Genus GRIMMIA, Ehrh.

The species of the Genus Grimmia sometimes form conspicuous gray tufts, often hoary from the white hair-points which terminate the leaves; sometimes they form soft fragile patches on exposed rocks of higher mountain regions. The tufts vary in size from little dense cushions one-third of an inch high, to the mats of Gr. hypnoides, whose stems attain a length of eight inches.

The dingy colour of their leaves, tipped with long or short white hairs is their most striking character. The chlorophyll is not only absent from the hair-point but often from the apex of the leaf-blade as well, thus adding to the grayish-white appearance of the tufts. The plants are usually short, with forked stems, crowded with lance-shaped leaves, frequently thickened along the margin, which is mostly entire; the vein is percurrent or extends into the transparent hair; the cells of the lower part are rectangular, of the upper part small, often obscure.

The generic name was given in honour of J. F. C. Grimm, a German botanist, who was a physician of Gotha.

The spore-cases are oval and smooth, borne on arched or straight pedicels. The peristome consists of sixteen red, lance-shaped teeth, entire or cleft at the apex and often perforated below.

There are about two hundred and forty species known at present, fifteen of them in North America.

Grimmia apocarpa, Hedw.

Habit and habitat.--Loosely tufted to form olive-green or black tufts on rocks or stone walls or even on roofs. There are varieties which grow in streams.

Name.--The specific name apocarpa from without and a fruit, was given by J. G. Hedwig, in 1787, to describe the hidden spore-case.

Plant (gametophyte).--Robust, the stems one inch long, branching in pairs, free from root-like fibres.

Leaves.--Lance-shaped, open when moist, erect when dry; apex sometimes slightly toothed, the upper leaves usually prolonged into a short, rough hair about one-quarter as long as the leaf; the base is concave, becoming keeled upward; margin recurved; the vein continued into the transparent hair, or vanishing below the apex; cells, the basal rectangular, then narrow, the upper rounded.

Leaves at the base of the pedicel (perichoetial leaves).--Broader, thinner; vein narrow; apex with or without short point.

Habit of flowering.--Male and female flowers on separate part of the same plant (autoicous); male flower-clusters bud-like.

Veil (calyptra).--Very small, not reaching below the lid, lobed at the base.

Spore-case.--Egg-shaped, almost concealed in the leaves at the base, red.

Pedicel.--Very short.

Lid (operculum).--Bright-red, tipped with a sharp point; columella attached to the lid and falling with it.

Annulus.--None.

Teeth (peristome).--Arising below the mouth, large, purple-red, entire or perforated, spreading when dry.

Spores.--Mature in winter.

Distribution.--Universal.