Lunularia

LUNULARIA

          

DIVISION: BRYOPHYTA

CLASS: HEPATICOPSIDA

ORDER: MARCHANTIALES

FAMILY: LUNULARIACEAE

                                       GENUS: LUNULARIA (CRESCENT CUP LIVERWORT)

 

GENERAL CHARACTERS

•PLANTS WITH AIR CHAMBERS AND PORES ON THE DORSAL SURFACE

 •CAPSULE HAS INVOLUCRE

 •PLANT WITH GEMMAE CUP ON ITS DORSAL SURFACE

 •GEMMAE CUPS ARE SEMI LUNATE IN SHAPE

 •THE NAME LUNULARIA REFERS TO MOON SHAPED CUPS

 •THE THALLUS IS GREEN OR YELLOWISH GREEN

 •THE THALLUS IS GLOSSY AND HAVE A POLYGONAL AREAS WITH A CENTRAL AIR PORE

 •VENTRAL SURFACE OF THE THALLUS BEARS ROW OF DELICATE HYALINE OR PARTIALLY PURPISH SCALES ON EACH SIDE OF THE MEDIAN LINE

 •MIDDILE OF THE SCALE IS  A HYALINE PARTIALLY PURPISH APPENDAGE OF CIRCULAR TO RENIFORM SHAPE

 •SMOOTH WALLED AND TUBERCULATE RHIZOIDS AREPRESENT

 •GROUPS OF DISC SHAPED  GEMMAE ARE PRESENT ON THE UPPER SURFACE OF THE THALLUS AND PROTECTED ON THE POSTERIOR SIDE BY THE CRESCENT SHAPED RIDGE

•THE CRESCENT SHAPED GEMMAE CUP IS THE DISTINCTIVE FEATURE OF GENUS

 

•THE GEMMAE IS ATTACHED TO A SHORT STALK

 •THE MATURE GEMMAE CAN BE DETACHED AND FLOAT AWAY IN WATER AND FAVOURABLE CONDITION IT GROW INTO A NEW PLANT

 

HABIT AND DISTRIBUTION

•LUNULARIA PREFERS MOIST, SHADY,AND COLD PLACES OF ROCKY SOIL

 •THE GENUS REPRESENTED IN INDIA BY A SINGLE SPECIES Lunularia crusiata WHICH IS FOUND IN DARJEELING, SIMLA, KODAIKANAL, AND MADRAS

 GAMETOPHYTE 

EXTERNAL FEATURES

•PLANT BODY IS GAMETOPHYTE AND THALLOID

 •THE THALLUS IS PROSTRATE DORSIVENTRALLYFLAT LARGE 

 •THE DORSAL SURFACE OF THE THALLUS HAS POLYGONAL AREA EACH WITH AN AIR PORE AND CRESCENT OR LUNATE SHAPED GEMMAE CUP

 •THE VENTRAL SURFACE HAS SMOOTH WALLED AND TUBERCULATE RHIZOID

 •THE VENTRAL SCALES ARE IN TWO LONGITUDINAL ROWS 

 INTERNAL STRUCTURE

•IT HAS TWO DISTINCT ZONES 

•THE DORSAL UPPER PHOTO SYNTHETIC ZONE IS MADE UP OF SINGLE LAYER OF AIR CHAMBERS WHICH OPEN OUT SIDE THROUGH SIMPLE HALF BARREL SHAPED AIR PORES

•EACH AIR PORE IS FORMED BY FIVE CONCENTRIC RING  AND RING IS MADE UP OF SIX CELLS

•EACH AIR CHAMBER HAS UNBRANCHED PHOTOSYNTHETIC FILAMENT WHICH ARE GREEN CHLOROPHYLLOUS AND 2-3 CELLS IN HEIGHT

 •THE VENTRAL LOWER ZONE OF THALLUS IS CALLED STORAGE ZONE WHICH IS MADE UP OF PARENCHYMATOUS CELLS CONTAINING STARCH GRAIN AND NUMEROUS OIL CELL CONTAINING SINGLE LARGE OIL BODY WHICH IS BROWN IN COLOUR 

 

    

Reproduction

Vegetative reproduction 

•The plants of lunularia mostly reproduce vegetatively in favorable 

conditions by following method : 

•Fragmentation: any fragment containing growing points when detached from main thallus either by external means on by death and decay of older part of the thallus develops into an independent pant.

 •Gemmae formation: the most elegant and interesting method of vegetative reproduction is by the formation of discoid green gemmae which are produced inside lunate shaped gemmae cup. In lunularia it is pocket like structure which is semilunar in shape. 

 the detached gemmae when come out from these pocket like semilunar

 Gemmae cups are dispersed on soil either by wind or by water.

 EachGemmae soon germinate and form a new thallus.  

 

       

 

Sexual reproduction

Antheridia

 •They are produced on disciform , sessile antheridial receptacle present at the apices of short branch of main thallus.

 •The antheridia are formed in acropetally order in median region of male receptacle.

 •Each antheridium is found enclosed with in a chamber called antheridial chamber which opens outside through an opening called ostiole. 

 •Development structure dehiscence of antheridium is marchantia type.

 Archegonia

 •They are produced on deeply four lobed stalked female receptacle (archegoniophore)  which emerges from the sinus of thallus.

 •The stalk of archegoniophore is short hairy and without rhizoidal furrow and photosynthetic tissue.

 •It is surrounded at the base with scales the archegonia has a covering  which protects horizontal, tubular involucre having wide mouth which facilitates fertilization.

 •The disc has no pore and photosynthetic tissue.

 •It is a characteristic feature of monotypic family lunularia.

Sporophyte

•The mature sporophyte consist of a small green foot colorless seta and a dark  brown capsule contains spore elaters.

•It enclosed in the involucre.

•The capsule is oval in shape its wall lack annular thickening and at the top there is a minute cup.

•The mature capsule open lengthwise to the base into 4 valves.

•The spore are tetrahedral with radiate marking.

•Elaters are bispiral and tapering at the end.