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The Primitive Mosses

Genus ARCHIDIUM, Brid.

The species of the Genus Archidium are minute terrestrial plants having stems with branches short and erect or long and prostrate.

The leaves are narrowly or broadly lance-shaped; with a vein; the cells are loose and contain but little leaf-green.

The spore-cases are terminal, sessile and globular, opening irregularly and transversely for the exit of the spores, which are few, smooth and larger than those of any other moss.

There are thirty-five species in all, five of them in North America. Their structure is more simple than that of most mosses; and for this reason Bridel gave it the generic name Archidium from the Greek, a beginning.

Archidium Ohiense, Schimp.

Habit and habitat.-Moist meadows and waste fields.

Name.-The specific name Ohiense refers to the fact that this moss was first found in Ohio.

Plant (gametophyte).-Minute; stems slender.

Leaves.-Narrowly lance-shaped, spreading; apex awl-like, finely toothed; vein extending into the apex of the leaf-blade.

Leaves at the base of the spore-case (perichaetical leaves).-Broader and longer.

Habit of flowering.-Male and female flowers in separate clusters on the same plant (autoicous).

Veil (calyptra).-Very thin, irregularly torn below.

Spore-case.-Spherical, on short side branch.

Pedicel.-Very short.

Lid (operculum).-Wanting.

Teeth (peristome).-Wanting.

Spores.-Sixteen to twenty, angular, smooth, mature in fall and winter.

Distribution.-North America, Ohio and southward.

Genus ASTOMUM, Hampe

The species of the Genus Astomum are minute, simple or branching plants, living in matted tufts on the ground.

The leaves are lance-shaped, tufted and curling toward the apex of the stems.

The spore-cases are erect and symmetrical on a short pedicel and are immersed in the leaves. They have distinctly formed, beaked lids, which are not easily detached. There are no teeth.

The generic name Astomum, from a, privative, without, and, a mouth, was given because when first known this moss was supposed to have no lid.

There are seventeen species in all.

Astomum Sullivantii, Schimp.

Habit and habitat.-In fields and gardens, living from year to year.

Name.-The specific name Sullivantii was applied to this moss by Wilhelm Philipp Schimper, in honour of William S. Sullivant, a noted bryologist.

Plant (gametophyte).-Minute, simple, or branched.

Leaves.-The lower leaves small, narrowly oval; the upper narrowly lance-shaped, densely tufted, covered on the back with tiny projections papillosa; curled in various directions when dry; apex pointed; margins rolled in; vein round, extending beyond the apex of the leaf-blade (percurrent).

Habit of flowering.-Male and female flowers on the same plant (monoicous).

Veil (calyptra).-Split up one side.

Spore-case.-Bright orange, symmetrical.

Pedicel (seta).-Shorter than the spore-case.

Lid (operculum).-Short, conical.

Teeth (peristome).-None.

Spores.-Bright, rusty brown, mature in autumn.

Distribution.-North America.

Genus GYMNOSTOMUM, Hedw.

The species of the Genus Gymnostomum are found in matted tufts on the ground and on limestone walls and rocks.

The plants have slender stems branching twice or many times to form clusters, with terminal erect spore-cases, cylindrical or globose, exserted on erect pedicels.

The leaves are small, generally larger upwards and tufted at the apex of the stem; they are lance-shaped with a solid vein prominent on the back.

The lid is long-beaked and falls to permit the escape of the spores. There are no teeth, a character which suggests the generic name, from the Greek, naked, and, a mouth.

There are fifty-five species in all, eight of them known in North America.

Gymnostomum calcareum, Nees & Hornsch.

Habit and habitat.-Densely tufted, bright-green above, rusty below; on shaded limestone rocks.

Name.-From calcarius, pertaining to lime, a name suggested by the plant's habit of depositing lime.

Plants (gametophyte). Stems 1/4 to 3/4 of an inch long, covered with rootlets.

Leaves.-The lower very small, gradually or abruptly larger upward; slender lance-shaped; apex blunt; vein extending to near the apex; margin minutely blunt-toothed.

Habit of flowering.--Male and female flowers on separate plants (dioicous).

Veil (calyptra).--Split up one side.

Spore-case.--Exserted, oblong, yellow-brown, slightly constricted under the mouth when dry.

Pedicel.--1/6 to 2/6 of an inch long.

Lid (operculum).--Base conical; beak awl-like.

Teeth (peristome).--None.

Annulus.--Short and persistent.

Spores.--Rare, mature in summer.

Distribution.--Universal.

Gymnostomum curvirostrum, Hedw.

Habit and habitat.--This moss is found on limestone rocks and on deposits of carbonate of lime about springs and streams. The plants obtain the carbonic acid gas (CO2) which they need, from bicarbonate of lime which is dissolved in the surrounding water. By decomposition of the bicarbonate of lime [H2Ca (CO3)2], which is soluble in water, the monocarbonate of lime (Ca CO3), which is insoluble in water is precipitated in the form of incrustations upon the leaves and stems of the moss, so that in time a very appreciable deposit of limestone is made.

Name.--From the Latin curvus, curved, and rostrum, a beak.

Plants (gametophyte).--Dark red or brown, matted, stems 1/2 to 5 inches long; branches of equal height, in close clusters, covered with a felt of red radicles.