No

1. Anthoceros
Bryophytes

2. Distribution and Habitat of Anthoceros:
•Anthoceros is represented by about 200 species.
• All species are terrestrial and cosmopolitan in
distribution.
•The species grow in very moist and shady places like
slopes, rocks or sides of the ditches.
•Some species are found growing on decaying wood
(Cavers, 1911). Unlike other bryophytes Anthoceros
is usually not well adapted to resist dry conditions.
•ఆంథోసెరోస్ యొక్క పంపిణీ మరియు నివాస:
ఆంథోలోరోస్ సుమారు 200 జాతులచే సూచంచబడుతుంది. అనిి జాతులు
పంపిణీలో భూమి మరియు కాస్మ ోపాలిటన్. ఈ జాతులు చాలా తడిగా మరియు
చీక్టి పరదేశాలోో వాలు, రాళ్ళు లేదా గుంటలు యొక్క భుజాలు వంటివి
పెరుగుతాయి. కొనిి జాతులు క్షయించే చెక్క మీద పెరుగుతాయి (కావెర్స్,
1911). ఇతర bryophytes కాక్ుండా Anthoceros స్ాధారణంగా పొ డి
పరిసిితులు అడుు కోవటానికి సవీక్రించారు లేదు

3. Systemic position

4. Habitat
• Distributed world wide
• Grows in shady and moist areas of
tropical and temperate regions
• About 200 species, and in Pakistan 3
common species are found in himaliyas
1.
2.
3.
Anthoceros himalayensis
Anthoceros erectus
Anthoceros chambensis

5. Vegetative morphology
Thallus
The plant body is gametophyte and
consist of small, dark green, prostrate
thallus
It is rosette like, and with lobes of whose
margins are divided into small lobed
segments
Dichotomous system is present
Surface of thallus is smooth, velvety , and
contains ridges and spines
Numerous thread like rhizoids are present
on ventral surface of thallus

6. Thallus

7. Internal structure of thallus
• There is no internal differentiation
• Parenchymatous cells are present
• Each contain single lens shaped
chloroplast
• Deep cells contain 2-8 chloroplasts
• Each chloroplast contains single
pyrenoid
• There are two surfaces, upper and
lower epidermis
• Lower epidermis contains mucilaginous
cavities that opens through a pore
called slime pore
• In these cavities blue green alga
resides.

9. Reproduction
Vegetative reproduction
Sexual reproduction

10. Vegetative
reproduction
1. Death of older plants: Vegetative reproduction takes place by thedeath of older parts.Younger
parts form new thallus.
2. Tuber: Some thallus forms tubers. These tubers are rich in stored fats and proteins. These
tubers germinate to on the margin of the lobes. They can survive long periods of drought.
Tuber detach and from new plants.
3. Gemmae: Gemma are also produced on short stalks on the upper surface of the thallus.
These are also act as vegetative reproductive bodies.
4. Persistent apices : in some species the thallus dies except the apices , there are called
persistent apices , they remain buried in soil and develop into new plant body during
favorable conditions

11. Vegetative reproduction

12. CLASSIFICATION
• KINGDOM : Plantae
• DIVISION: Anthocerotophyta
• CLASS: Anthocerotopsida
• ORDER: Anthocerotales
• FAMILY: Anthocerotaceae
• GENUS: Anthoceros

13. POSITION IN DIVISION

14. VEGETATIVE REPRODUCTION
• It takes place by the following methods:
• Progressive death and decay of thallus.
• By tubers.
• By Gemmae.
• By persistent growing apices.

15. Death and decay of thallus
• Not a very common
method. More
common in
Liverworts.
• Part of lobes form a
new gametophyte.

16. BY TUBERS
• Tubers have an outer protective corky layer and resist
extreme desiccation. They remain alive even after the
death of the thallus. In sufficient moisture, they germinate
and give rise to new plant.

17. By Gemmae
• Some species like A. glandulosus , A. formaosae and A.
fusiformis bear stalked structures on dorsal surface
called called gemmae. On separation from parent
thallus they give rise to new plants.

18. By persistent growing apices.
• Species like A. pearsoni and A. fusiformis
employ this method.
• Mostly in areas where summer season is very
dry.
• All parts of thallus except apical regions
become dry. These Apices later after period of
dormancy for new plant.

19. SEXUAL REPRODUCTION

20. ANTHERIDIA
• They occur
endogenously on
dorsal surface in a
closed cavity
called antheridial
chambers.
• They enclose mass
of androcytes
which mature into
antherozoids.

21. DEVELOPMENT OF ANTHERIDIA

22. Antheridium after maturation

23. Antherozoids
• The antherozoid is spindle like and biciliate.
• The cilia are attached to the anterior end of
the body.
• The antherozoids swim in the water by the
lashing moment of their flagella.

24. DEVELOPMENT OF ARCHEGONIUM
The development of archegonium begins from a single
superficial cell. This cell becomes prominent and acts as
archegonial initial.
The archegonial initial first divides vertically, producing three
jacket initials which surround an axial cell.
The axial cell divides transversely, producing a cover initial and
a central cell. Thereafter, the central cell divides by a
transverse wall, giving rise to a primary canal cell and a
primary venter cell.

26. Structure of archegonium
• A mature archegonium is
flask-like in shape, without
neck canal cells and with an
egg (oosphere) in its venter.
• At the top of the neck of the
archegonium there are four
cover cells, which become
separated from the
archegonium, as soon as the
gelatinization of the venter
and neck canal cells is over.

27. FERTILIZATION
• Prior to fertilization, the cover
cells become detached from
the archegonium, and the neck
canal cells become gelatinized.
Through the medium of water,
the antherozoids enter the
mouth of archegonium.
• Ultimately, one lucky
antherozoid penetrates the
egg, and the fertilization is
effected. The male and female
nuclei unite to each other,
producing a zygote (oospore)

28. DEVELOPMENT OF SPOROGONIUM
• With the result of the first vertical division, the
daughter cells are produced, which are subjected to a
transverse division producing four cells of equal or
unequal size
• These cells again divide vertically, developing
eightcelled embryo, four cells in each tier. The upper
tier of four cells divides transversely. This way the three
tiers of four cells each have been produced.
• The lowermost tier produces the foot, the middle tier
produces partly the foot and mainly the seta and the
upper-most tier produces the capsule.

29. SPOROGONIUM TISSUE
• In the young sporogonium,
the columella consists of
four vertical rows of the
cells, but later on it is made
up of sixteen rows of cells.
• The jacket initials divide
again and again periclinally
producing the 4 to 6 layered
wall of the capsule.
• Later on, the sporogenous
tissue becomes
differentiated into two types
of cells, i. e., (i) the
sporocytes (spore mother
cells) and (ii) the sterile cells
(pseudoelaters).

32. GERMINATION OF SPORE

33. LIFE CYCLE IN NUTSHELL

34. SCHEMATIC LIFE CYCLE

39. • Occurrence
• Polytrichum have worldwide distribution. They are very common in
cool temperature and tropical regions. Plants live in cool and shady
places.
• General structure
• The main plant body is gametophyte. The adult plant consists of
two parts: rhizome and upright leafy shoot.
• 1. Rhizome: It is horizontal portion and grows underground. It
bears three rows of small brown or colourless leaves. It also bears
rhizoids. The cells are rich in protoplasm and oil globules.
• 2. Upright leafy shoot: The leafy shoots are much longer. It is the
most conspicuous part of the plant. It arises from rhizome. These
branches consist of central axis. These branches bear large leaves
arranged spirally.

41. • 3. Leaves: Leaves have broad bases. Leaves in the
upper portion are green. But the lower ones are
brown. Each leaf has a broad. colourless
sheathing leaf base and narrow distal limb.
• The mid-rib forms the major part of the leaf.
These leaves possess extra photosynthetic tissue
in the form of closely set vertical plates of green
cells. These are known as lamellae. Green
lamellae act as additional photosynthetic tissue.

42. • Leaf: Polytrichum have complex internal structure. The mid-rib
region is thick. But the margins are only one cell thick. The lower
surface is bounded by epidermis. One or two layers of
sclerenchymatous tissues are present above the epidermis. The
central tissue of leaf is composed of thin-walled parenchymatous
tissues. Above this are again sclerenchymatous cells. The upper
surface is formed of a layer of large cells from which arise
numerous lamellae. This upper portion is the main photosynthetic
region of the leaf.
• Stem: The T.S. of stem shows three regions: medulla, cortex
and epidermis. The medulla is again differentiated into two zones:
central zone and peripheral zone. The cortex consists of thick-
walled cells. The innermost layer of cortex around the conducting
strands is known as a mantle. Its cells contain starch grain.
Epidermis is present over the cortex.

44. • Vegetative reproduction
• Vegetative reproduction takes place by
following methods:
• I. Protonema: The spores germinate to form
protonema. Several buds grow on the
protonema. Each bud by of its apical cell
develops into gametophyte.
• 2. These are also called vegetative buds.
They are formed on the rhizoids.
• 3. Fragmentation: The rhizome gives rise to
erect lea& shoots at intervals. Death or
breaking of shoots separates the erect
branches. These branches behave as
independent plants.