MUSCI FOLIOS', OR OPERCLI.ATI.
The Musci foliosi, or operculati, have the herb always divided into stems, roots, and leaves, and the fruit cover ed with a calyptra, and raised on a seta, or fruitstalk, except in the two genera Andraea and Sphagnum, in svhich it is sessile.
The capsule is always entire, except in Andraea, in which it is quadrivalve; and except in Phascum and Voitia, in which it is indehiscent, it opens by the sepa ration, by a transverse line, of a part teimed Opercialum or lid, from the summit of the capsule.
The natural character of this order is to have the flow ers monoecious, dioecious, sometimes united, or poly gamous.
Male Flowers.—Calyx polyphyllous, the leaflets ge nerally of the same colour with the leaves of the plant ; but frequently different in form and texture ; some times coloured ; spreading when the flowers are discoid, conniving when they are budlike.
Corolla none. Stamens several, within a polyphyl lous calyx, with succulent filarnents intermingled ; in some species they are aggregated into a capitulum, and raised on a stalk above the calyx ; in others, they are scattered in the axillx of the upper branches. Fila ment short (except in Sphagnum, in which it is some what elongated) filiform ; anther roundish, ovate, or cylindrical, consisting of a mass of pollen, contained in a case that usually opens by a lid.
Female Flowers.—Calyx a perichaetium, many-leaved, the leaflets oft more delicate in texture than the other leaves, enclosing several pistils, with succulent threads intermingled among them.
Corolla none, unless we describe under this name the loose exterior covering of the capsule, which is cy lindrical towards the base ; terminates upwards in a cone ; adheres at the summit to the capsule, and is free every where else, except (during the flower) at the base.
Pistil, cylindrical at the base, terminating above in a cone ; the style elongated, slender, covered to the very summit by the calyptra. The stigma truncated or con cave.
Pericarp, a capsule, entire except in Andrxa ; elevat ed on a fruitstalk, except in Sphagnum and Anclrxa ; opening by the separation of an operculum, except in Phascum and Voitia, in which it is indehiscent ; the mouth either naked, covered with a flat membrane, sur mounted by a conical membrane, or by teeth, which are always definite in number, except in Dawsonia, and either in a single or double row ; an elastic ring frequently present without the teeth; walls of the capsule always double, though in some instances very. closely approxi mated ; when the peristorne is double, one row of teeth usually arises from the summit of each. An upright pillar, termed Columella, which rises perpendicularly from the base to the summit of the capsule, and some times, as in Systilium splachnoides, and Hypnum dcn droides, continues attached to the operculum after the capsule is opened, is always present in this family.
Calyptra, torn by the elongation of the ft uit-stallt, or by thc enlargement of the capsule, either from the base, or by a nearly horizontal section about the middle ; oft split at one side ; in some instances very small and ca ducous; generally deciduous; very rarely persistent.