Moss
Peat moss (Sphagnum sp.)
The mosses ( Bryophyta ) are a division of plants and one of the three groups, which are summarized as mosses.
- 4.1 Notes and references
Features
Gametophyte
The protonema consists of thin, multicellular filaments. The gametophyte is always divided into stems and leaves. The stems have partially simple guide elements ( Leptoide and Hydroide ). The leaves are spirally placed, rarely they are three or two lines. In general, the papers are not dorsiventrally. In many cases, they have a multi-layered midrib. The leaves are never mehrspitzig; the lamina cells are round ( parenchymatous ) or elongated ( prosenchymatisch ). The rhizoids are multicellular, branched and provided with oblique cross walls. Oil components are, for the Bryophytina never before.
Sporophyte
The sporophyte has always a stalk ( seta ). The seta is growing, the maturation of the capsule in the length. The development of Sporogons takes five to 19 months. The capsule is pear-shaped to cylindrical, and usually has columella and peristome. It has a sloping lid, or the capsule is closed and opened by decay. The Kalyptra tears during the growth of the Sporogons from all around and is lifted up by the Seta. The Bryophytina do not elaters unlike the liverworts.
System
Holly Frey and divide the mosses as follows:
- Department of mosses ( Bryophyta ) Subdivision Takakiophytina class Takakiopsida
- Class Sphagnopsida
- Class Andreaeopsida
- Class Oedipodiopsida
- Class Tetraphidopsida
- Class Polytrichopsida
- Class Bryopsida
For an outline to see family level classification of mosses.
Fossil evidence
Fossil mosses are rare. The earliest evidence dates back to Devon. From all geological periods following are fossil evidence.
The best preserved specimens have been found in amber tertiary age ( Baltic, Dominican and Mexican amber ). Part of occurring in the Tertiary species is extant mosses, most of which are native to Southeast Asia, very similar.