BRYOPHYTES
Bryophyte means moss plant . They are regarded as amphibian of plant kingdom because they have terrestrial species as well as aquatic species . Dendroceros grow as epiphytes . Buxbaumia aphylla is saprophyte .
General characters
1. Gametophytic phase is dominant .
2. Plant body is made up of rhizoids ( not roots like pteridohytes ) , stem and leaves .
3. They lack vascular tissue ( unlike pteridophytes ) .
4. Sexual reproduction is oogamous type .
5. Sex organs are multicellular and with outer one celled thick sterile jacket ( characteristic feature ) .
6. Water is necessary for fertilization ( like algae ) .
7. Zygote does not has any resting period ( unlike algae ) , they immediately divide to form embryo ( not spores like algae ) after fertilization .
8. Embryo develops within archegonium .
9. Anthocerotales plastids are with pyrenoids ( like algae ) .
10 . Green moss protonema resembles filametous green algae .
11. Rhizoids absorp water , minerals and fix the plant to the substratum .
Origin of bryophytes
Anthoceros , sphagnum etc show resemblance with pteridophytes and green protonema in mosses resemble filamentous green algae .
Classification of bryophytes
Term bryophyta was coined by Braun . Prof. Shiv ram kashyap is father of Indian bryology . His book is Liverworts of western himalalayas and the Punjab plains . Prof. S K pandey of Rae Bareli and Prof. Ram Udar of Basti are also famous .
Bryophyta is divided in to 3 classes -
1. Hepaticopsida = Hepaticae = Liverworts -
Plant body is thalloid or foliose . Thalloid plant bodies are prostate , lobed and dichotomously branched . Archesporium develops from endothecium . Some imp orders are Marchantiales , jungermanniales .
2. Anthocerotopsida = Anthocerotae = Hornworts - Plant body is flat , dorsiventral and thalloid . Tuberculate rhizoids and scales are absent . Intercellular mucilage cavities open up on ventral surface by slit like slime pores . Sex organs are embedded on dorsal surface of the thallus . Sporogenous tissue develops from amphithicium . Elaters do not have thickening bands and are called pseudolaters . Imp order is anthocerotales .
3. Bryopsida =Musci = Mosses - Gametophyte has 2 growth stages - protonema stage and leafy gametophyte stage . Some imp sub-classes are sphagnobrya ( order sphagniales ) , eubrya or brydae ( order funariales ) . Bryidae ( Eubrya ) is the most highly evolved group of bryophyte and are called true mosses . Operculum and peristomial teeth are characteristics of brydae ( eybrya ) .