Dr. Somendra Sharma
Why Study Bryophytes? Importance, Types
The term Bryophyta came from the word ‘Bryon’ which means moss and python means
plants. Bryophyta includes embryophytes like mosses, hornworts, and liverworts. These are
the plants that grow in shady and damp areas and are small in size. They lack vascular
tissues. They reproduce through spores instead of producing flowers and seeds. Despite the
fact that most bryophytes lack complex tissue organization, they exhibit a wide range of
forms and ecology. They are found all over the world and are relatively small in comparison
to most seed-bearing plants. The study of bryophytes is called Bryology.
Why are Bryophytes Called Amphibians of Plants?
Bryophytes are called “amphibians of the plant kingdom” because they’re terrestrial plants
but require water to finish their life cycle at the time of sexual reproduction.
General Characteristics of Bryophytes:
Plants occur in damp and shaded areas.
The plant body is thallus-like, i.e. prostrate or erect.
It is attached to the substratum by rhizoids, which are unicellular or multicellular.
They have a root-like, stem-like, and leaf-like structure and lack true vegetative
structure.
Plants lack the vascular system (xylem, phloem).
The dominant part of the plant body is the gametophyte which is a haploid.
The thalloid gametophyte is divided into rhizoids, axis, and leaves.
The gametophyte bears multicellular sex organs and is photosynthetic.
The antheridium produces antherozoids, which are flagellated.
The shape of an archegonium is a sort of a flask and produces one egg.
The antherozoids fuse with an egg to make a zygote.
The zygote develops into a multicellular sporophyte.
The sporophyte is semi-parasitic and dependent on the gametophyte for its nutrition.
Cells of sporophyte undergo meiosis to form haploid gametes which form a
gametophyte.
The juvenile gametophyte is known as protonema.
The sporophyte is differentiated into foot seta and capsule.
Classification of Bryophytes
According to the newest classification, Bryophyta is split into three classes:
, A. Hepaticopsida (Liverworts)
B. Anthocerotopsida (Hornworts)
C. Bryopsida (Mosses)
A. Hepaticopsida (Liverworts):
The name hepaticopsida comes from the word “hepatic” which means liver. Liverworts come
under this class. Liverworts are a type of bryophyte that belongs to this group. It has around
900 species. The most basic bryophytes are liverworts. They prefer moist rocks and wet soil
to live in. Because they dwell near water, their chances of drying are much reduced.
A gametophyte is a type of plant. It can be thalloid (flat) or ribbon-like (ribbon-like), and is
generally dichotomously branched. Marchantia, for example, is linked to the soil by rhizoids.
Other species, such as Porella, tend to grow erect and are deceptively leafy, that is,
differentiated into a fake stem and leaves. The gametophyte provides nutrition and protection
to the sporophyte. The sex organs form towards the terminals of the branches on the upper
surface of the thallus. As in Marchantia, they sometimes form distinct branches on
gametophytes called antheridiophores and archegoniophores.
Hepaticopsida is Further Divided into 4 Orders:
1. Marchantiales (e.g. Riccia, Marchantia)
2. Sphaerocarpales (e.g. Sphaerocarpos)
3. Calobryales (e.g. Calobryum)
4. Jungermanniales (e.g. Pellia)
The Main Characteristics of the Class Hepaticopsida are:
The gametophyte plant is either thalloid or foliose.
Thalloid forms are dorsiventral, lobed, and dichotomously branched.
Rhizoids are unicellular, branched, and septate.
Sex organs are borne dorsally embedded in gametophytic tissues.
The sporophyte is a compilation of only capsule (in Riccia) or foot, seta, and capsule
(in Marchantia).
The columella is absent in the capsule.
Sporogenous tissues develop from endothecium.
Reproduction:
Asexual Reproduction:
It takes place by the formation of gemmae or by the process of fragmentation.
Gemmae are produced inside gemma cups. Gemmae are green and multicellular and
Why Study Bryophytes? Importance, Types
The term Bryophyta came from the word ‘Bryon’ which means moss and python means
plants. Bryophyta includes embryophytes like mosses, hornworts, and liverworts. These are
the plants that grow in shady and damp areas and are small in size. They lack vascular
tissues. They reproduce through spores instead of producing flowers and seeds. Despite the
fact that most bryophytes lack complex tissue organization, they exhibit a wide range of
forms and ecology. They are found all over the world and are relatively small in comparison
to most seed-bearing plants. The study of bryophytes is called Bryology.
Why are Bryophytes Called Amphibians of Plants?
Bryophytes are called “amphibians of the plant kingdom” because they’re terrestrial plants
but require water to finish their life cycle at the time of sexual reproduction.
General Characteristics of Bryophytes:
Plants occur in damp and shaded areas.
The plant body is thallus-like, i.e. prostrate or erect.
It is attached to the substratum by rhizoids, which are unicellular or multicellular.
They have a root-like, stem-like, and leaf-like structure and lack true vegetative
structure.
Plants lack the vascular system (xylem, phloem).
The dominant part of the plant body is the gametophyte which is a haploid.
The thalloid gametophyte is divided into rhizoids, axis, and leaves.
The gametophyte bears multicellular sex organs and is photosynthetic.
The antheridium produces antherozoids, which are flagellated.
The shape of an archegonium is a sort of a flask and produces one egg.
The antherozoids fuse with an egg to make a zygote.
The zygote develops into a multicellular sporophyte.
The sporophyte is semi-parasitic and dependent on the gametophyte for its nutrition.
Cells of sporophyte undergo meiosis to form haploid gametes which form a
gametophyte.
The juvenile gametophyte is known as protonema.
The sporophyte is differentiated into foot seta and capsule.
Classification of Bryophytes
According to the newest classification, Bryophyta is split into three classes:
, A. Hepaticopsida (Liverworts)
B. Anthocerotopsida (Hornworts)
C. Bryopsida (Mosses)
A. Hepaticopsida (Liverworts):
The name hepaticopsida comes from the word “hepatic” which means liver. Liverworts come
under this class. Liverworts are a type of bryophyte that belongs to this group. It has around
900 species. The most basic bryophytes are liverworts. They prefer moist rocks and wet soil
to live in. Because they dwell near water, their chances of drying are much reduced.
A gametophyte is a type of plant. It can be thalloid (flat) or ribbon-like (ribbon-like), and is
generally dichotomously branched. Marchantia, for example, is linked to the soil by rhizoids.
Other species, such as Porella, tend to grow erect and are deceptively leafy, that is,
differentiated into a fake stem and leaves. The gametophyte provides nutrition and protection
to the sporophyte. The sex organs form towards the terminals of the branches on the upper
surface of the thallus. As in Marchantia, they sometimes form distinct branches on
gametophytes called antheridiophores and archegoniophores.
Hepaticopsida is Further Divided into 4 Orders:
1. Marchantiales (e.g. Riccia, Marchantia)
2. Sphaerocarpales (e.g. Sphaerocarpos)
3. Calobryales (e.g. Calobryum)
4. Jungermanniales (e.g. Pellia)
The Main Characteristics of the Class Hepaticopsida are:
The gametophyte plant is either thalloid or foliose.
Thalloid forms are dorsiventral, lobed, and dichotomously branched.
Rhizoids are unicellular, branched, and septate.
Sex organs are borne dorsally embedded in gametophytic tissues.
The sporophyte is a compilation of only capsule (in Riccia) or foot, seta, and capsule
(in Marchantia).
The columella is absent in the capsule.
Sporogenous tissues develop from endothecium.
Reproduction:
Asexual Reproduction:
It takes place by the formation of gemmae or by the process of fragmentation.
Gemmae are produced inside gemma cups. Gemmae are green and multicellular and
