Spore Sac

Sphagnales also have a dome-shaped spore-sac continued over the columella, and, though their capsule opens by an operculum, they differ widely from other mosses in the development of the sporogonium as well as in the characters of the sexual generation. ❋ Various (N/A)

In all other Bryales there is a definite columella extending from the base to the apex of the capsule, the archesporium is derived from the outermost layer of cells of the endothecium, and an air space is formed between the spore-sac and the wall. ❋ Various (N/A)

C, Median longitudinal section of a capsule, with the seta gradually widening into the apophysis at its base; d, operculum; p, peristome; a, annulus; c, columella; s, archesporium; h, air-space between the spore-sac and the wall of the capsule. ❋ Various (N/A)

In the Polytrichaceae another air space separates the spore-sac from the columella. ❋ Various (N/A)

Immediately around this is the layer of cells from which the spores will be developed (s), and the layers of cells on either side of this form the walls of the spore-sac, which will contain the spores. ❋ Various (N/A)

Between the wall of the capsule, which is composed of several layers of cells, and the spore-sac is a wide intercellular space ❋ Various (N/A)

There is a short, wide columella, over which the dome-shaped spore-sac extends, and no air-space is present between the spore-sac and the wall. ❋ Various (N/A)

The layer of cells immediately around the endothecium becomes the spore-sac, and an air-space forms between this and the wall of the capsule. ❋ Various (N/A)