Mosses (Musci)

Mosses (Musci) are considered the more advanced members of Bryophyta, distinguished by an erect plant body.

Gametophytic phases. The gametophyte passes through two successive stages:

1. Protonema stage — a prostrate, green, branched, filamentous stage, also called the juvenile gametophyte. It bears numerous buds, and because a new leafy plant can arise from each bud, the protonema is the means of vegetative propagation in mosses.
2. Leafy stage — arises from a bud on the protonema. It has an erect, slender, stem-like main axis (called the cauloid) bearing spirally arranged, leaf-like structures (called the phylloid). It is fixed to the soil by multicellular, branched rhizoids, and it is this leafy stage that bears the sex organs.

Vegetative reproduction in mosses also occurs through fragmentation and budding of a secondary protonema.

Examples. Funaria, Polytrichum, Sphagnum. …