Usually the gemmae arise by the outgrowth of superficial cells, and become free by breaking away from their stalk.
In Blasia and Marchantia the gemmae are formed within tubular or cup-shaped receptacles, out of which they are forced by the swelling of mucilage secreted by special hairs.
Erect branches may arise from the protonema, and gemmae may be developed on it.
Apart from the separation of branches by the decay of older portions, special gemmae are found in many species.
Targionia is found on exposed rocks, but the other forms are less strikingly xerophytic; Marchantia polymorpha and Lunularia spread largely by the gemmae formed in the special gemma-cups on the thallus, and occur commonly in greenhouses.
Besides this, gemmae may be formed on the protonema, on the leaves or at the apex, and some mosses have specialized shoots for their better protection or distribution.
Thus in Georgia the stalked, multicellular gemmae are borne at the ends of shoots surrounded by a rosette of larger leaves, and in Aulacomnium androgynum they are raised on an elongated leafless region of the shoot.
That they should have no sexes, reproductive organs, and two sorts of gemmae, or sexes, reproductive organs, or gemmae of one evident kind?
The real gemmae of the Hepaticae puts the question of gemmae out of doubt.
The gemmae formed on submerged Mucors may bud like a yeast, and even bring about alcoholic fermentation in a saccharine solution.
In addition to sporangia and the conidial spores referred to, some Mucorini show a peculiar mode of vegetative reproduction by means of gemmae or chlamydospores--i.
Thallus thickened in the middle by a keeled costa, usually conspicuously porose, with dark purple scales beneath; gemmae none.
Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmae in crescent-shaped receptacles.
Gemmae globose, issuing by a slender ascending tube from large flask-shaped receptacles which are immersed in the thallus.
These gemmae fall to the ground and their axis grows into the stem of a new plant, as specimens collected in 1854 show very plainly.
Thallus dichotomous, copiously reticulate and porose, with a narrow costa; gemmae none.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "gemmae" in a variety of sentences. We hope that you will now be able to make sentences using this word.
