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Four-toothed Mosses — Part 1

Genus GEORGIA, Ehrh.

The species of the Genus Georgia are erect, growing in clusters but not matted, on the ground, on rotten wood and sandstone.

The lower leaves are small, distant and scale-like; the upper leaves are longer, broadly lance-shaped, close and tufted at the apex of the stems; the vein reaches to below the apex; the cells are somewhat six-sided, less crowded and linear rectangular at the base. Linear root-leaves (frondiform) or whip-like leafy branches are often present. These frondiform leaves appear in some species only in the protonemal stage, while in other species they persist at the base.

The spore-cases are cylindrical or oval on long slender, smooth, brown pedicels which are straight or abruptly bent. The lids are conical with mitre-like veils. The four teeth arising from just below the rim of the box are a conspicuous character of the genus. They are formed by the splitting of a solid mass of pithy tissue within the lid into four slender triangular segments, red and slightly furrowed on the back. A cross section of a tooth shows it to be triangular and composed externally of large transparent cells and internally of small thick-walled pointed cells. There is no annulus.

There are but two species known and both of these are found in North America.

The genus was named by Friedrich Ehrhart, in honour of King George III of England, whom he considered one of the greatest patrons of botany.

Georgia pellucida, Rabenh.--See Colour Plate III.

Habit and habitat.--Erect, rather densely crowded, bright-green above, red below. On decayed wood in damp places, common.

Name.--The specific name pellucida from the Latin per, through, and lucida, transparent, refers to the texture of the leaves, which are very translucent.

Plant (gametophyte).--Stems of two kinds, (1) the fertile 1/2 to 1 inch long, pale red, simple or branching in pairs, fibrous at the base with crowded leaves tufted at the summit of the stem; (2) gemmae-bearing, the gemmae disk-like with short stalks, greenish, transparent, inclosed in a rosette of 4 to 5 bracts.

Leaves.--The lower leaves are small, remote, erect, appressed, broadly lance-shaped and red; the upper leaves are larger, broader, not lying against the stem; margin entire; vein vanishing below the apex; cells round-hexagonal above, elongated and rectangular at the base. It is not an uncommon thing to find gemmae which have fallen from the cups, entangled and growing among the leaves.

Leaves at the base of the pedicel (perichoetial leaves).--Lance-shaped, sheathing elongated, rather obtuse.

Habit of flowering.--Male and female flowers on the same plant (monoicous); male flower-clusters bud-like at the apex of the shoots which arise in pairs.

Veil (calyptra).--White below, more solid and red above, mitreform, reaching to the middle of the spore-case, irregularly folded lengthwise into 8 or 9 ridges, somewhat ragged at the base.

Spore-case.--Erect, elongated, cylindric, pale-brown with the mouth red.

Pedicel (seta).--Straight, smooth, purple; when dry twisted to the left in the lower part, to the right above, 1/2 to 3/4 of an inch long.

Lid (operculum).--Thin, conical, straight or oblique,

Annulus.--None.

Teeth (peristome).--Four, erect, brown, pyramidal, grooved lengthwise on the back, arising from below the rim of the spore-case.

Columella.--Slender, cylindrical.

Spores.--Small, smooth, green, mature from July to September.

Distribution.--Widely in America, Europe and Asia.

Georgia geniculata, Girgens.

Georgia geniculata may be distinguished from G. pellucida in having the pedicel suddenly bent near the middle, a character which suggested the specific name geniculata from the Latin geniculum, a little knee.

It is found in Japan and in North America.