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Herbarium — Part 8

Veil (calyptra).-Very small, erect, conical, with a long beak.

Spore-case.-Orange, spherical, immersed.

Pedicel.-Very short.

Lid (operculum).-None.

Teeth (peristome).-None.

Spores.-Mature in winter and early spring.

Distribution.-Europe, Africa, and North America.

Genus PHASCUM, Linn.

The plants of the Genus Phascum are very small with simple distinct stems. They grow in loose clusters on bare ground under old willows and along brooks and garden paths. The protonema is not persistent.

The leaves are crowded, forming small heads and are lance-shaped with taper-pointed apex and a broad base with a vein extending as an awn beyond the apex. The cells are distinct and pale below, smaller and green above, sometimes with minute projecting points on one or both faces.

The spore-cases are spherical or egg-shaped with a short point or a blunt beak. They are raised on a short, erect or curved pedicel and break irregularly and transversely for the emission of the large, rough spores, which are borne on a thick, central column (columella).

There are ten species known in all, three of them in North America. By some they are believed to be mosses in a primitive condition; by others they are believed to be degenerate forms of higher mosses.

The generic name Phascum is derived from the Greek, an ancient name for a moss. It was originally applied by Theophrastus to a lichen, Usnea barbata, and first used as a generic name for these mosses by Linnaeus in 1753. He enumerated three species, all founded on figures made by Dillenius and published in 1741. Schreber limited the name more closely to its modern sense. In a quaint little pamphlet printed in 1770, he praises the invention of lenses which make it possible to see the tiny mosses as if they were of greater stature, and says that the ancients spoke well and wisely when they said "Nature is never more perfect than in small things."

Phascum cuspidatum, Schreb.

Habit and habitat.-In loose yellow-green tufts in old fields.

Name.-The specific name cuspidatum, pointed, refers to the apex of the leaves.

Plants (gametophyte).-Stems simple or branched, 1/10 to 5/10 of an inch high, often bushy with numerous fertile stems, dividing from the base or branching above, occasionally whip-like.

Leaves.-Small and few below, much larger and crowded above, broadly lance-like, twisted when dry: apex awl-like; margins recurved, entire; vein thick and extending beyond the apex; basal cells large, clear; upper cells small, green, with tiny projecting points.

Habit of flowering.-Male and female flowers on the same plant (monoicous); male flowers sessile in the axils of the upper leaves.

Veil (calyptra).-Split on one side.

Spore-case.-One or several on a plant, erect or nodding, spherical with a sharp point at the top, 1/20 of an inch in diameter.

Pedicel.-Short and curved, immersed or slightly emergent.

Spores.-Brown, rough, mature in March and April.

Distribution.-North and South America, Europe, Asia, Africa.

Genus PLEURIDIUM, Brid.

The plants of the Genus Pleuridium are minute and erect with simple or branching stems clustered to form dense cushions on the ground.

The leaves are small and few below, but longer and crowded above; they are oval at the base, tapering to a long awl-like point with a broad vein forming most of the apex.

The spore-cases are solitary and terminal, immersed on a short pedicel. They are almost spherical with a point on the summit and a persistent columella.

There are thirty-six species known in all, five in the United States.

The generic name Pleuridium is derived from the Greek, at the side. The name is suggestive of the position of the spore-cases, which in some species appear to be on the sides of the stems instead of on the summits, because a side branch has grown from near the base of the spore-case-but in the same direction as the main stem-leaving the spore-case behind.

Pleuridium subulatum, (Huds.), Rabenh.

Habit and habitat.-In loose bright-green and silky tufts on earth and clay, along woods, banks and heaths.

Name.-The specific name subulatum, from the Latin subula, an awl, refers to the shape of the upper leaves.

Plants (gametophyte).-Minute, 1/10 to 2/10 of an inch high, simple or branching.

Leaves.-The lower distant, short, oval and taper-pointed; the upper longer, more crowded, spreading; apex an awn minutely toothed and rough on the back; vein broad, forming most of the awn.

Habit of flowering.-Male and female flowers close together on the same plant (paroicous); male flowers naked in the axils of the leaves at the base of the spore-case.

Veil (calyptra).-Split on one side.

Spore-case.-Immersed in the leaves at the base, egg-shaped with a tiny point at the apex (apiculate).

Pedicel (seta).-Short, immersed.

Lid (operculum).-None.

Teeth (peristome).-None.

Spores.-Rough, mature from March to June.

Distribution.-Quite universal.

Genus BRUCHIA, Schwaegr.