The male and female flowers of mosses may in gene 'al be distinguished without much difficulty, even with out opening the perichxtial leaves. The male (lowers, when axillary, are more rounded at the base; are shorter, and have an appearance of greater firmness and com pactness than the axillary female flowers. When the flowers of the one sort are axillary, and of the other ter menal, there can be no difficulty ; yet even then oft the same distinctive marks prevail.
The essential parts of the flower consists of stamens and pistils.
The stamens, as already mentioned, usually occttpy a separate flower from the pistils. They are always nu nietous ill the same flower. They consist of a filament, usually short, but in Sphagnum of considerable length, and a mass of pollen similar to that of the Asclepiadeae, contained in a double membrane, situated upon it. The fornt of this mass is usually cylindrical ; but in the genus Sphagnum, and in Bryum androgynum, it is ovate, and somewhat acuminated. In Sphagnum, it appeals to be surrounded, in the perpendicular direction, by a ring. The membrane containing the mass of pollen never separates from the filament, unless owing to external violence. Its colour is in every instance a light green.
If placed in a drop of water in a concave glass, the colour becomes lighter, it enlarges ; and when its con tents are about to be emitted, it is nearly pellucid. At last it opens at the summit, either irregularly, as in Sphagnum, ot by a sort of lid, as in most other mosses, and emits, with force, a transparent viscid fluid, with numerous coloured granules intermingled. Afterwards, the empty exteriur of the mass shrinks ; it becomes divided into large reticulations ; its colour becomes yellowish, and at last its sides fall together.
This process may easily be observed also, without the aid of water. The figure of it given by Hedwig, in 11/2eor. General. et Pruett': Plant. Crypt. t. xi. was taken in the dry state, under the solar microscope.
This is the account given by Hedwig in the second edition of the work just alluded to, (Leipsix, I798,) and which has now approved itself to the botanical world in general. In the former edition of the same work, and in his other previous writings, Hedwig described mosses as possessing true anthers or bags containing a dry pollen, and even figured repeatedly the pollen in the act of escaping. But subsequent and more accurate observa
tion convinced him that this was a mistake.
Generally, in both male and female flowers of mosses, occur a great number of succulent jointed threads. In some species they retain the same thickness from the base to the summit, and terminate acutely or obtusely ; in othcrs they swell towards the summit into various forms. In Dicranutn pellucidum, they are slightly club-shaped, Bryum triquetrurn, very evidently so. They terminate in incrassated globular joints in Bar tramia fontana, Bryurn punctatum. After becoming club-shaped, the last joint forms an apiculus in Bryum hornuni ; in Funaria hygrornetrica, they vary in form. The threads, however, which are thus incrassated to wards the summit, occur only in some terminal male flowers, and never in those that are axillary. In a few rare instances, the threads are altogether wanting, as in the male flowers of Grimmia pulvinata. When present, they are compared by Hedwig to the nectaries of other flowers, affording a moist halitus, well fitted to promote the emission of the fluid, which constitutes most of the mass of pollen.
The pistils of mosses, with a few rare exceptions, among which is the genus Sphagnum, always occur se veral together in the same flower. In Sphagnum they are solitary. In the female flowers of Diphyscium fo liosum, six pistils always occur ; in Encalypta ciliata, and Dicranum bryoides, seven; in Enealypta vulgaris, ten ; and in Bryum hornum, twenty. But of thesc, general, only one becomes ft uit-bearing ; the rest soon wither, though they persist. Yct in Bryurn ligulatunt and punctatum, Dicranum scopariurn, and some other spe cies, lye frequently find several capsules arising. from the SaIlle perichxnum. The sterile pistils, being at first supposed by lledwig to be of no other use than to assist the fecundation of the fertile one, by making the flowers larger, and thus favouring- the ingress of pollen, were at that time named by hint adductors. But he afterwards renounced this idea ; considered all the pistils as equally susceptible of fecundation ; and the use of SO many in a flower to be, that at least one capsule from it might be se'cured. They consist always or three parts, the stigma, style, and germen.