Marchantiales, Anthocerales and Polytrichales : A comparision

Bryophytes
Liverworts
Hornworts and
Mosses

1. BRYOPHYTES Marchantiales , Anthocerales and Polytrichales Dr. K. Kannathasan Assistant Professor of Botany APA COLLEGE OF ARTS & CULTURE, PALANI 624 601

2. Marchantiales Anthocerales Polytrichales Distribution Widely distributed Tropical and warm temperate Tropical and temperate countries Genus and Species 35 and 420 6 and 300 15 and 350 Examples Marchantia , Targionia , Reboulia , Riccia , Plagiochasma Anthoceros , Notothylas , Megaceros , Dendroceros Polytrichum , Pogonatum , Atrichum , Oligotrichum , Lyellia Gametophyte External Strictly thallose Green, flat and thick, dichotomous branch Apical notch, Areole Smooth and tuberculate rhizoids, Scales Lobed thallose,Without regular dichotomous branch, Scales and tuberculate rhizoids absent, Highly organised Leaf-distal limb and proximal sheathing base Lamellae Gametophyte Internal Two distinct region Photosynthetic and Storage region. Air pores and chambers present One region Air pores and chambers absent, mucilage cavity present Epidermis, Cortex and Central Strand

3. Thallus ̶ External Marchantia Anthoceros Polytrichum

4. Thallus ̶ Internal Marchantia Anthoceros Polytrichum Stem Leaf Rhizome

5. Sexual Reproduction Antheridiophore Anthoceros Polytrichum Marchantia Archegoniophore Antheridium Archegonium Antheridium Archegonium

6. SPOROPHYTE Marchantia Anthoceros Polytrichum

7. Marchantiales Anthocerales Polytrichales Asexual Reproduction Fragmentation ( Riccia , Marchantia ) Adventitious branches ( Targionia , Riccia ) Gemma ( Marchantia , Lunularia ) Tuber( Riccia ) Fragmentation, Gemmae , Tubers, Persistent growing apices and apospory Vegetative buds (Bulbils) Death or breakage of rhizoids Sexual Reproduction Sex organs : dorsal, acropetal order Sessile or stalked Sunken, Antheridia surrounded by perigonial cluster Archegonia surrounded perichaetial leaves Sporophyte Calyptra:cover Foot, seta and capsule Capsule wall single layer Elaters present Foot, intercalary meristematic zone and capsule Capsule 4 to 6 layer Psudoelaters present Columella Operculum Peristome Capsule several layers

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