Funaria - Class 11 PDF Download

Systematic Position

Division :   Bryophyta

Class    :   Bryopsida

Order   :   Funariales

Family :   Funariaceae

Genus  :   Funaria

Species:   Funaria hygrometrica

Distribution & Habitat 

Funaria hygrometrica is a cosmopolitan species.

The plants (mosses) are found in damp and shady localities.

Tallest moss is Dawsonia.

The adult plant body of moss represents Gametophytic phase.

It is found in two forms :

(a)  Protonema : Prostrate, Creeping filament, Ephemeral, Multicellular and filamentous algae like – [Juvenile stage]

(b)  Gametophore : [Erect and Foliose]

• Gametophore is an actual gametophytic plant which measures 1-3 cms and distinguished into three parts-

(i) Rhizoids (ii) Axis (iii) Leaves

Rhizoids :

1. Rhizoids are brownish in colour.
2. Branched, Cylindrical, Multicellular and Oblique septate structure.

Function :

They help to fix the plant and in the absorption of water and minerals.

Axis :

• It is green in colour, erect, soft and branched.
• Their branches are extra axillary in origin. It means branches are developed from below the leaves, not from their axis.
• Stem (axis) and branches bear bright green leaves.

Leaves :  

1. Leaves are small, membranous, sessile and oval shaped and a distinct mid-rib is present.
2. They are arranged (3/8 phyllotaxy) spirally on the axis. In leaves, lateral vein are absent.
3. 3/8 phyllotaxy i.e., in three complete spirals there are eight leaves.

Note : A pyramidal shape apical cell is responsible for the growth of apex of axis.

Internal Structure 

1.   Axis or stem : A transverse section of the mature axis shows three distinct regions.

(a)  Epidermis : It is the outermost layer, composed of tangentially elongated chlrophyllous cells. It has no stomata and cuticle.

(b)  Cortex : It is multilayered parenchymatous region. The cells of outer layers are thick walled and the cells of inner layers are thin walled.

(c)  Central Cylinder : It is composed of long, colourless and thin walled cells. These cells are dead and lack protoplasm. They help in the conduction of water and nutrients.

2.   Leaf : In the V.S. of leaf lamina one multilayered median vein is found and its both side having single layered wings.  

• The multilayered median vein is the main part. The central part of median vein formed by narrow parenchymatous cells.
• Wing region of leaf lamina made up of thin layered cells in which many chloroplasts are present.
• Stomata are absent in the leaf.  

Reproduction

Reproduction in gametophyte of Funaria is of two type-

(1) Vegetative  (2) Sexual 

1. It is responsible for gregarious habit.
2. Vegetative propagation in Funaria takes place by the following method.

Fragmentation of primary protonema 

• On germination the spore gives rise to a branched filamentous structure, known as primary protonema. 
• Sometimes it breaks into small fragments. The fragments bear buds and each bud develops into an erect gametophore.

(ii)  Secondary protonema 

• Under favourable conditions. Secondary protonema may be formed by the cells of injured rhizoids, stems, leaves or reproductive structures.
• Like primary protonema, it bears buds which are capable of growing into erect gametophores. 

 (iii) Bulbils 

• They develop on rhizoids and devoid of chloroplast. The bulbil grows into a new plant when detached from the parent plant.

 Sexual Reproduction

1. Sexual reproduction in Funaria is oogamous type.
2. Funaria is monoecious and autocious plant.
3. Male and female sex organs are called antheridia and archegonia respectively and are borne in clusters at the tips of different branches.
4. Antheridia develops at the apex of main branch of plant where as archegonia develops at the apex of lateral branch.
5. These are covered by involucral leaves.

[Note : Autocious means when two different sex organs are born on different head of the same plant.]

ANTHERIDIUM

1. Antheridium of Funaria is club shaped structure.
2. It has short multicellular stalk.

It has single layer jacket.

In Antheridium many androcytes are present. Each androcyte forms long, spirally coiled, biflagellated antherozoids by metamorphosis.

Chloroplast is present in jacket cells of young antheridium due to which they are green but orange colour of jacket of mature antheridium is due to presence of chromoplast.

At the apex of jacket two colourless cells are present called as opercular cells or cap cells.

In between the antheridia, paraphysis are present which are green, upright and multicellular capitate hairs.

Antheridia and paraphysis are surrounded by perigonial leaves. 

Function of paraphysis : Provide protection to antheridia and water secretion.

A mature archegonium is flask shaped structure paraphysis are also present between archegonia which are not capitate. They are surrounded by perichaetial leaves.

Archegonium is distinguished into stalk, venter and neck.

A swollen double layered venter contain an egg and a venter canal cell.

Neck contains six or more (6-10) neck canal cells. It is capped by four cover cells.

Jacket of neck is single layered and made of six vertical rows of neck cells.

In each vertical row 6 to 9 neck cells are present.

FERTILIZATION

Water medium is essential for fertilization and the apical cells of the antheridium Jacket which forms operculum absorbs water and bursts.

The spirally coiled biflagellate antherozoids escape from the antheridium.

The neck canal cells and venter canal cells also degenerate to form a mucilaginous substance which absorb water to exert a pressure so cover cells become separated from each other and to form a passage for antherozoids.

The antherozoids are attracted towards the neck of the archegonium by some chemotactic substance, possibly sugar, produced by archegonium.

An antherozoids fused with egg of archegonium to form a diploid zygote.

Diploid zygote divides to produce sporophyte of Funaria.

The mature sporophyte distinguished into three parts : Foot, seta and capsule.

(i)   Foot : Foot is very small and formed by parenchymatous cells. It absorbs water and nutrients from the gametophyte.

(ii)  Seta : Seta is a thick and thread like structure. It is hygroscopic in nature.

Function :

• Conducts water and nutrients.
• Helps in dispersal of spores. 

(iii) Capsule : 

• It is pear shaped, the capsule is distinguished into three regions.

Development of capsule takes place by upper apical cell of embryo.

(i)   Upper  Opercular region 

(ii)  Middle  Theca region 

(iii) Lower  Apophyseal region - Stoma

(i)   Opercular region :

• The opercular region comparises operculum which covers peristome.
• The peristomial teeth are present in peristome. They are curved and triangular in shaped.
• They are arranged in two whorls-outer and inner whorls.
•  Outer whorls bear 16 teeth which are thick, large and well developed & red.
• Inner teeth are also 16 in number but they are thin and delicate & colourless.
• Total 32 peristomial teeth are present.
• These teeth are help in dispersal of spores.
• The teeth are simply the strips of cuticle and they are acellular.
• Opercular region is separated by theca region, by two rings.
• Rim or Diaphragm (lower)
• Annulus (upper)

(ii)  Theca region : 

• The middle theca region is distinguishable into epidermis, hypodermis, chlorenchymatous region (2-3 layered), filamentous trabeculae with large air spaces, two layered spore sacs and central sterile region is columella.
• Elaters are absent in spore sac.

Function of columella :  It provides water and food to developing spores in spore sac.

Function of trabeculae : It connects the inner most layer of capsule wall to outer most layer of outer wall of spore sac.

(iii) Apophyseal region :

• The apophyseal region is the lower most part of the capsule which has conducting strand and attached with seta.
• This is surrounded by chlorenchymatous cells with prominent intercellular spaces.
• The epidermis has stomatal aperture which is guarded by two guard cells. 
• In mature stomata stomatal aperture is guarded by single ring like guard cell.

Note : 

• The endothecium forms the central parenchymatous cells in the opercular region.
• Columella, Inner wall of spore sacs, archesporium in the fertile region, central conducting strand in the apophyseal region and central conducting strand in seta region.
• The rest of the tissues arises from the amphithecium.
• Archesporial cells divide and redivide, to form a mass of sporogenous tissues.
• Sporogenous cells behave like spore mother cells.
• These cells are divided by meiosis and to form haploid tetrahedral tetrad of spores.

1. Funaria is a stegocarpous moss.
2. Stegocarpous means the dehiscence of capsule always along a predetermined line.
3. As the capsule matures, the thin-walled cells including columella dries up.
4.  The thin walled cells of annulus break away and thus operculum separated along the annulus and exposing the peristome.
5. The hygroscopic nature of outer peristomial teeth (Open out in only in dry weather) helps in dispersal of spores. 
6. The inner peristomial teeth check sudden dispersal of spores.
7. They reach at far places through the medium of air.
8. In moss capsule, spore dispersal takes place by censor mechanism.
9. Peristome teeth- They shows xerochasy.
10. Spore is the first cell of gametophytic generation. Spores are spherical in shape and 12-20mm in diameter and double layered.
11. The outer wall-exosporium is much thicker and inner wall endosporium is thin.
12. Spores have oil droplets and chloroplast.
13. The spore germinates to form the primary protonema.
14. Protonema grows in two directions. The green prostrate branches growing on the surface called as chloronema or chloronemal branches and colourless branches grow into soil are called rhizoidal branches.
15. The chloronemal branches give rise to many buds and each bud grows into an erect leafy gametophore.

Funaria is a protoandrous moss.

Internal structure of Sphagnum stem is differentiated into central medulla, cortex and epidermis.

Medulla has hadrome. Hadrome is water conducting tissue and it is made up of parenchyma.

Stem of Sphagnum contain special type of water storage cells are called “retort cells”(Star shape or bottle neck like cells.).

Upper region of capsule is covered by membranous structure called calyptra. Calyptra is formed by venter of archegonium. So it is gametophytic tissue or paternal tissue (n).

The sterile tissue of capsule can be divided into four regions.

1. The sterile cells constituting the apophysis.
2. The sterile cells forming thick capsule wall.
3. The sterile cells forming columella.
4. The sterile cells constituting the operculum and peristome.

Polytrichum : (Hair cap moss) : 

1. Dioecious
2. Vegetative reproduction – by bulbils (Which develop on rhizoids) and fragmentation of underground) rhizome.
3. Neck canal cells – Ten
4. Annulus absent.
5. In Polytrichum, peristome teeth (32 or 64) are not hygroscopic.
6. Common name – Hair cap moss.

Sphagnum – Peat moss / Bog moss / Turf moss.

Peristome teeth absent