Short note on thallus structure of Anthoceros

            Short note on thallus structure of Anthoceros

The genus Anthoceros is also known as hornworts due to to its appearance. It belongs to the family anthocerotaceae.

Habitat:
The member is cosmopolitan in distribution. The main availability e of the plant group is temperate and tropical region of the world. The best habitat for the members is mainly the moist shady places on soil, damp rocks, on woods etc.

Plant structure:
the main dominant plant body is gametophyte, latter on the sporophyte develops on the gametophyte.

Gametophyte plant body is discussed in two points ie. morphology and anatomy.

Morphology or external structure:
the plant body is dark green dorsiventral, prostrate thallus. The thallus is thick, variously lobed in margins and does not have any midrib. The dorsal surface of the thallus is smooth and the ventral surface has numerous smooth walled rhizoids. In the ventral surface some dark blue-green spots are found which represent the micro-colonies of Nostoc (a blue green algae).

Anatomy or internal structure:
Internal cellular difference is almost absent. in both the surface, the most outer layer is one cell layer thick epidermis. the epidermal cells are small sized with lens shaped chloroplast each having single pyrenoid.
The inside tissue to epidermis is not distinguished into individual photosynthetic and storage region. All the cells are parenchymatous having chloroplast with single pyrenoid. Cells are without any intercellular spaces.
Towards ventral region some intercellular cavities with mucilage are found, known as mucilage cavities. These cavities have minute openings at ventral surface known as slime pores, through these pores the blue green algae like Nostoc enters and starts to get colonized to form endosymbiotic relationship with the thallus.
On the ventral surface of the thallus  smooth walled  rhizoids are found. Reproductive units develop at the dorsal surface.