2. Marchantiales Polytrichales
Distribution Widely distributed Tropical and
temperate countries
Genus and
Species
35 and 420 15 and 350
Examples Marchantia, Targionia,
Reboulia, Riccia,
Plagiochasma
Polytrichum,
Pogonatum,
Atrichum,
Oligotrichum, Lyellia
Gametophyte
External
Strictly thallose
Green, flat and thick,
dichotomous branch
Apical notch, Areole
Smooth and tuberculate
rhizoids,
Scales
Highly organised
Leaf-distal limb and
proximal sheathing
base
Lamellae
Gametophyte
Internal
Two distinct region
Photosynthetic and
Storage region.
Air pores and chambers
present
Epidermis, Cortex
and Central Strand