Bryopsida – funaria

Bryopsida – Funaria (Moss)
Vaishali S.Patil
Assosiate Professor, Department of Botany
Shri Shivaji College of Arts, Commerce & Science
Akola

Division: Bryophyta
Class: Bryopsida
Subclass: Funariidae
Order: Funariales
Family: Funariaceae
Genus: Funaria
Habit-
210 species.
•Grows in dense patches or cushions
in moist shady and cool places during
the rainy seasons. These are primitive
multicellular, autotrophic, amphibious
plants. It can also be found on moist
walls and the crevices of rocks and places where recent fires have taken
place

External structure-
•The plant body is green, soft, and upright, about half an inch
tall (3–5 cm).
• It shows a radial symmetry with a differentiation of an axis
or stem, leaves or phylloids are multicellular colorless
branched rhizoids with oblique septa. The main axis of the
plant, which is upright, bears a set of spirally sessile leaves
having a clearly distinguishable midrib.
•The obovate leaves form a bulb-like cluster at the top of the
shortish, long stem. The leaves are long with an acute apex
and weakly serrate margins. The midrib ends just below, or
extends just beyond the leaf apex. They reproduce by spore
formation.
•They have no vascular system. Plant body consists of a long,
twisting stalk (seta) with an asymmetrical,grooved capsule
(spore-bearing part of the plant i.e.sporophyte) at the tip.

•At the apex of the main plant axis,the antheridium is borne.
This is the male part of the shoot. A lateral branch from the
main plant axisbears the female shoot archegonium at
its meristem.

Internal Structure:
1. Axis or stem
The transverse section (T. S.) of axis can be differentiated into
three distinct regions:
(i) Epidermis
(ii) Cortex
(iii) Central conducting strand or central cylinder.
(i) Epidermis:
It is the outer most single layered protective covering
consisting of small tangentially elongated chlorophyll bearing
cells. Cuticle and stomata are absent.
(ii) Cortex:
It is present between the epidermis and conducting tissue. It is
made up to parenchymatous cells. Younger part of the cortex

contains chloroplasts but in the older part they are lacking. At maturity
few outer layers of cortex become thick walled and are reddish brown in
colour but those of the inner layers become thin walled.
(iii) Central Conducting Strand:
It is made up of long, narrow thin walled dead cells which lack
protoplasm. These cells are now commonly called as hydroids.
Conducting strand besides providing a certain amount of mechanical
support, functions in the upward conduction of water and solutes.

.
2. Leaf:
Transverse section (T. S.) of ‘leaf’ shows a well-defined
midrib with two lateral wings. Except the midrib region,
the ‘leaf’ is composed of single layer of parenchymatous
polygonal cells. The cells contain many large and prominent
chloroplasts. The central part of the mid rib has narrow
conducting strand of thick walled cells which help in
conduction

Reproduction -
i) Vegetative Reproduction:
1. By multiplication of primary protonema:
In Funaria, spores on germination form a branched, filamentous,
multicellular structure. It’s called primary protonema. In it certain
colourless separation cells are formed by intercalary divisions. These cells
die out and break up the protonema into single cell or many celled
fragments. These fragments grow into new protonemata which bear buds.
Each bud develops into a leafy gametophore.
2. By secondary protonema:
When protonema is developed by other than the germination of spore, it is
called secondary protonema. It may be developed from any detached
living part of the gametophyte such as ‘stem’, ‘leaves’, antheridium,
archegonium paraphysis, sterile cells of capsule, seta or when the rhizoids
are exposed to sun light in moist atmosphere . It is similar to primary
protonema and develops into leafy gametophore.

3. By Gemmae:
During unfavorable conditions, the terminal cells of the protonemal
branches divide by transverse, longitudinal divisions and form green
multicellular bodies of 10-30 cells. These are called gemmae. At maturity
gemmae become slightly reddish brown in colour. On the return of
favourable conditions gemmae germinate and form new plants.
4. By Bulbils:
When such gemmae like structures are produced on rhizoids inside the
substratum, these are called bulbils. These are devoid of chloroplasts but
capable of developing into leafy individuals under favourable conditions.

5. Apospory:
Development of gametophyte from sporophyte without the formation of
spores is known as apospory. Any vegetative cell of the sporophyte may
form green protonemal filaments which bear lateral buds. These buds
later develop into leafy gametophores.
The gametophores thus formed are diploid. Sexual reproduction in such
gametophores results in the formation of tetraploid (4n) zygote. The
sporophytes from tetraploid are sterile because they are not capable of
bearing spores.
ii) Sexual Reproduction -
Sexual reproduction is oogamous. Male reproductive structure is known
as antheridium and female as archegonium. Funaria is monoecious
(having male and female sex organs on the same thallus) and autoicous
(antheridia and archegonia develop on separate branches of the same
thallus). Sex organs are borne on leafy gametophores in terminal clusters.
The main shoot of the leafy gametophore bears antheridia and act as
male branch. Female branch develops as a lateral outgrowth from the
base of the male branch and bears archegonia. It grows higher than the

male branch. Funaria is protandrous (antheridia mature before the
archegonia). It ensures the cross fertilization.
Male Branch or Antheridiophore: Longitudinal section (L. S.) of male
branch shows that its apex is expanded and convex shaped. It bears large
number of reddish brown or orange antheridia in different stages of
development. Projected antheridia are surrounded by a rosette of
spreading leaves called perigonial leaves.
The antheridial cluster with surrounding perigonial leaves is called
perigonium. The antheridia are intermingled with large number of sterile
hair like club shaped structures called paraphyses . Paraphyses store
water, protect developing antheridia, help in photosynthesis and
dehiscence of antheridia.

Structure of an Antheridium:
The antheridium is club shaped. It can be differentiated into two
parts:
(a) Short multicellular stalk
(b) Body of antheridium.
Body of antheridium has sterile, single layered jacket of polyhedral
flattened cells. When young the cells of the jacket contain chloroplasts
which turn orange or reddish brown at maturity. Jacket encloses a large
number of androcytes (antherozoid mother cells).
At maturity the distal end of the antheridium
bears one or two thick walled, colourless
cells called operculum.
The opercular cells become mucilaginous,
absorb water and swell, break
connections with the neighbouring cells and
form a narrow pore. Androcytes ooze out
in the form of a viscous fluid through this
pore.

Female Branch or Archegoniphore:
The female branch arises from the base of the male branch. Longitudinal
section (L. S.) of female branch shows that many archegonia
intermingled with paraphyses occurs at its apex. The terminal cell of
paraphyses is not swollen. The cluster of archegonia is enclosed by a
group of green foliage ‘leaves’ called perichaetial leaves. The
archegonial cluster with the surrounding perichaetial leaves is called
perichaetium.
Structure of an Archegonium:
A mature archegonium is flask shaped structure. It remains attached to
the female branch by a massive stalk. It consists upper elongated slender
neck and basal globular portion called venter .
The neck is slightly tubular, twisted, single layered and consists of six
vertical rows of neck cells, which enclose an axial row of ten or more
neck canal cells. The venter wall is two layered and encloses venter canal
cell and egg cell. Venter canal cell is situated just below the neck canal
cells.

Fertilization in Funaria:
Water is essential for fertilization. The opercular cells of the antheridium
rupture and releases mass of antherozoids. When archegonium reaches at
maturity, the neck canal cells and venter canal cell disintegrate to form a
mucilaginous mass. It absorbs water, swells up and comes out of the
archegonial mouth by pushing the cover cells apart. This mucilaginous
mass consists chemical substances (mainly sugars).
The cover cells of the neck separate widely from each other and form a
passage leading to the egg. Rosette like perigonial leaves serve as splash
cup from which rain drops disperse antheroziods to some distance (rain
drops falling on the archegonial cluster situated at lower level).
Many antherozoids enter the archegonial neck because of chemical
response but only one of them fuses with the egg to form the zygote.
Union of male and female nuclei is complete within 10 hours.
Fertilization ends the gametophytic phase.

Sporophytic Phase:
Zygote is the first cell of the sporophytic phase. Development of
sporophyte takes place within the venter of the archegonium.
Structure of Sporophyte:
The sporophyte is semi-parasitic in nature, the mature sporophyte can be
differentiated into three distinct parts—foot, seta and capsule.
(i) Foot:
It is the basal portion of the sporogonium. It is small dagger like conical
structure embedded in the apex of female branch. It functions as
anchoring and absorbing organ.
(ii) Seta:
It is long, slender, stalk like hygroscopic structure. It bears the capsule at
its tip. It raises the capsule above the apex of leafy gametophore.

(iii) Capsule:
It is the terminal part of the sporophyte and is developed at the apex of
the seta. It is green in colour when young but on maturity it becomes
bright orange coloured. It is covered by a cap like structure called
calyptra. (gametophytic tissue develops from the upper part of the
archegonium).
Internal Structure of the Capsule:
Longitudinal Section (L.S.) of the capsule shows that it can be
differentiated into three distinct regions-apophasis, theca and operculum.
(a) Apophysis:
It is the basal sterile part of the capsule. It is bounded by the single
layered epidermis which is interrupted by stomata. The sotmata have
single ring like guard cells. Below the epidermis is spongy parenchyma.
The central part of the apophysis is made up of elongated thin walled
cells forming a conducting strand. It is called neck of the capsule. It is
the photosynthetic region and connects seta with capsule.
(b) Theca:
It is the middle, slightly bent spore bearing region of the capsule. It lies

between the apophysis and operculum.
Longitudinal section (L. S.) passing through the theca shows the
following regions:(i) Epidermis:
It is the outer most layer. It is single layered with or without stomata.
(ii) Hypodermis:
It is present below the epidermis. It consists two to three layers of
compactly arranged colourless cells.
(iii) Spongy parenchyma:
It consists two to three layers of loosely arranged chlorophyllous cells. It
is present inner to hypodermis. These cells are capable to manufacture
their own food but dependent on gametophyte for water and mineral
nutrients. Therefore, the sporophyte of Funaria is partially dependent on
gametophyte.
(iv) Air spaces:
These are present just below the spongy parenchyma and outside the
spore sacs. Air spaces are traversed by green cells (chlorenchymatous
cells) called trabecular (elongated parenchymatous cells).

(v) Spore sac:
These are present below the air spaces on either side of the columella. It
is ‘U’ shaped and broken at the base. (It separates its both arms).
It has an outer wall (3-4 cells thick) and an inner wall (single cell in
thickness). Between the outer wall and inner wall is the cavity of the
spore sac. When young, the cavity of the spore sac is filled with many
spore mother cells. At maturity the spore mother cells divide by meiotic
divisions and form many haploid spores.
(vi) Columella:
It is the central part of the theca region. It is made up of compactly
arranged colourless parenchymatous cells. It is wide above and narrow
below, connecting the central strand of apophysis. It helps in conduction
of water and mineral nutrients.
(c) Operculum:
It is the upper region of the capsule. It is dome shaped and consists four
to five layers of cells. The outermost layer is thick walled and called
epidermis. Operculum is differentiated from theca by a well-marked
constriction. Just below the constriction there is a diaphragm (rim).

It is composed of two to three layers of radially elongated pitted cells.
Immediately above the rim is annulus which consists of 5-6
superimposed layers of cells. Its upper cells are thick but two lowermost
layers of cells are thin. Annulus separates the theca from the operculum.
Below the operculum lies the peristome . It is attached below to the edge
of the diaphragm. The peristome consists of two rings of radially
arranged peristomial teeth. In each ring there are sixteen teeth.
The teeth are not cellular but they are simply the strips of the cuticle. The
teeth of the outer ring are conspicuous, red with thick transverse bands
while the teeth of the inner ring are small, delicate, colourless and
without transverse bands. Inner to peristome teeth lies a mass of thin
walled parenchymatous cells.

Dehiscence of the Capsule:
Funaria is a stegocarpous moss (dehisce along a pre-determined line)
Dehiscence of the capsule is achieved by ‘breaking off’ of annulus. As
the capsule matures it becomes inverted due to epinasty. The thin walled
cells of the annulus break away, the operculum is thrown off and the
peristome teeth are exposed.
The outer peristomial teeth (exostome) are hygroscopic. The inner
peristomial teeth (endostome) do not show any hygroscopic movements
but act as a sieve allowing only a few spores to disperse at a time. The
lengthening and shortening of the outer peristomial teeth help in the
dispersal of spores.
In high humidity the exostome absorb water, increase in length and curve
inwards. In dry weather, the exostome teeth lose water, bend outwards
with jerky movements. It allows the dispersal of spores from the capsule
in instalments. At maturity the seta also shows jerky movements.
Twisting and swinging of seta in dry weather further aids in the dispersal
of spores.

Structure and Germination of Spore:
Spore is the first cell of the gametophytic phase. Each spore is spherical ,
12-20 µ in diameter and surrounded by two wall layers . The outer wall
is thick, smooth, brown and known as exosporium, while the inner wall
is thin, hyaline and called endosporium. Spore wall encloses single
nucleus, chloroplasts and many oil globules.
Under favourable conditions (sufficient moisture) spores germinate.
Exosporium ruptures and endosporium comes out in the form of one or
two germ tubes. Each germ tube is multicellular, green with oblique
septa. The germ tube grows in length, divides by septa to form green
algal filament like structure called primary protonema.

Primary Protonema:
It is the juvenile (young) stage of the gametophyte formed by the
germination of spore. It forms two different types of branches.
Most of the branches grow horizontally on the moist surface of the soil
and are known as chloronemal branches (positive phototrophic, thick and
rich in chloroplast) while some branches grow down in the soil and are
called rhizoidal branches (non-green, thin and possess oblique septa).
These branches can develop chlorophyll if expose to light.
Rhizoidal branches function as anchoring and absorbing organs while
chloronemal branches develop minute green buds behind the cross walls
which develop into leafy gametophores. From one primary protonema
many moss plants develop, so the moss is gregarious in habit. Primary
protonema is short lived.
According to Sirnoval (1947) development of protonema under
laboratory conditions can be differentiated into two stages—chloronemal
stage and caulonemal stage. Chloronemal stage is characterised by
irregular branching, right angle colourless cross walls, and many evenly
distributed discoid chloroplast.

It is positive phototropic but never produce buds. Nearly after 20 days
chloronemal stage matures into caulonemal stage. This stage is
characterised by regular branching brown cell walls, oblique cross walls
and fewer chloroplasts. It is negative phototropic and produce buds
which later develop into leafy gametophores. Rhizoids arise from the
base of a bud.

Bryopsida – funaria

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