Morphological, anatomical and reproductive characters of Marchantia

Morphological, anatomical and reproductive characters of Marchantia

1. Marchantia – Morphology, anatomy and reproduction Sankrita Gaonkar Assistant Professor in Botany [email protected]

2. Contents Classification of Marchantia Morphology, anatomy and reproductive characters of Marchantia References

3. Marchantia Classification: Class: Hepaticopsida Order: Marchantiales Family: Marchantiaceae Genus: Marchantia

4. Gametophyte: Morphology: Thallus – prostrate, dichotomously branched and dorsiventral Dorsal surface – rhomboidal or polygonal area are found Each small area has small pore at centre Thallus – 2 to 10 cm Midrib – groove on ventral surface Rhizoids – smooth-walled and tuberculate Gemma cups – dorsal surface – gemmae (vegetative bodies) Antheridiophores (male) and archegoniophores (female) – reproductive structures – on different thalli Strictly dioecious - heterothalli

5. Anatomy: Upper surface – single layered epidermis – less number of chloroplast Air-pores – on upper epidermis Photosynthetic region Air chambers – beneath upper epidermis Partition wall – separates air chambers Photosynthetic filaments – in air chambers Storage region: Storage tissue – parenchyma cells – contain starch Oil and mucilage cells are present

6. Reproduction: vegetative and sexual Vegetative reproduction: i ) by death and decay of older parts of thallus – decay below dichotomy and apices separate ii) adventitious branches – ventral surface of thallus iii) gemmae – in gemma cup

7. Sexual reproduction: Antheridiophore Receptacle – disc on stalk – male and female sex organs Male receptacle – flat and lobed Convex at upper face Air pores present on upper epidermis Flask-like cavities in air chambers Ostioles – opening of antheridial cavity Antheridium – short stalk, single layered jacket, androcytes Antherozoid – elongated, uninucleate, biflagellate Dehiscence – in presence of water

8. Archegoniophore Consists of a stalk bearing lobed disc It is 8 lobed structure Growing spices bend downwards and inwards towards stalk Rays – cylindrical structures from margin of disc – give stellate form to female receptacle Oldest archegonia towards disc periphery and youngest towards stalk Perichaetium – plate-like tissue on either sides of archegonial groups

9. Archegonium structure Flask-shaped Elongate neck and bulbous venter Neck – jacket cells – 6 vertical rows Neck canal cells – 4 or more Venter – single jacket layer – large egg and venter canal cells Cover cells – top of neck Perigynium ( pseudoperianth ) – collar-like structure at base of venter – formed after fertilization Dehiscence –presence of moisture Venter

10. Sporophyte 3 regions: foot, seta and capsule Foot – bulbous, absorptive structure at base Seta – elongated – connects foot and capsule Capsule – oval, single layered jacket Within jacket layer – spores and sterile elaters (helps in spore dehiscence) Spore dispersal – capsule mature and come out of 3 layers (calyptra, perigynium and perichaetium) with the help of seta

11. References Vashishta BR. 2010. Botany for degree students: Bryophytes. S. Chand & company ltd. Pandey B.P. (2009). Botany for degree students: B.Sc. First Year. S. Chand & Company Ltd. New Delhi.