The topic discussed here is the characteristic of Bryophytes with examples such as Riccia & Marchantia. The complexity in their reproductive structures and also the sporophyte is also discussed. Funaria an example of moss gives the details about the living habits of these organisms which are considered to be advanced bryophytes.

1. BRYOPHYTES

3.  They are found in moist, cold shady places. None of
them are marine.
 The plant represent two morphologically distinct
generations i.e. gametophytic and sporophytic.
 Gametophytic phase is the dominant phase.
 Plant body in primitive forms like Riccia and
Marchantia are thalloid, but in mosses like Funaria,
it is differentiated into rhizoids, stem and leaves.

4.  The thalli of Riccia & Marchantia is attached to substratum by
unicellular, unbranched rhizoids but mosses like Funaria,
rhizoids are branched, multicellular.
 The plant body is made up of simple thin walled
parenchymatous cells.
 Xylem, Phloem (Vascular bundle )and mechanical tissue
(Sclerenchyma) are all lacking in bryophytes.
 Bryophytes are found in moist places due to the following
reasons :
 In the absence of true roots, cells are able to absorb water directly
from the ground or atmosphere.
 Biflagellate sperms of bryophytes need water for their movement to
reach archegonium (female sex organ) for fertilization.
MARCHANTI
A

5.  Bryophytes reproduce vegetatively by tubers, gemmae,
fragmentation etc.
 Male sex organ is called antheridium.
 Antheridium is made up of mass of androcytes enclosed by sterile
jacket.
 Each androcyte gives rise to bi-flagellate sperms (male gamete).
 Sexual reproduction is of oogamous type.

6.  The female sex organ is called Archegonium.
 Each archegonium is a multicellular flask-shaped structure.
 Its lower part is called Venter, and slender elongated upper part is
called neck.
 Sex organs are multicellular and jacketed.
 Venter encloses egg (female gamete) and venter canal cell.
 Neck encloses a row of neck canal cells.
 The syngamy (fertilization)takes place in water. The sperms swim
n water to reach near the archegonium.
RICCIA : FEMALE
REPRODUCTIVE
ORGANMARCHANTIA :
FEMALE
REPRODUCTIVE
ORGAN

7. ARCHEGONIOPHOR
E
ANTHERIDIOPHOR
E

8.  The zygote undergoes continuous division without any resting period.
 The developing embryo is retained inside the venter, where it finally
develops into Sporogonium.
 The sporophytes (sporangia) are partially or completely dependent
upon gametophyte.
 The sporogonium is usually differentiated into foot, seta and capsule.
 In Riccia foot and seta are absent. Capsule is embedded in the thallus.
 In capsule meiosis occurs in spore mother cells to form haploid spores.
 The spores are homosporous i.e. only of one type-
 Haploid spores, germinate into gametophytic thallus or may form
filamentous protonema which then bears adventitious roots and gives
rise to leafy plant
Riccia SPOROPHYTE
Marchantia
SPOROPHYTE

10.  Depending on the characters of the gametophyte the
bryophytes are divided into to groups
 Liverworts &
 Mosses.

11.  Plant body is thalloid, green, dorsiventral and dichotomously
branched.
 On the dorsal side a longitudinal groove is present.
 Cup shaped bodies gemmae cups are present on dorsal side.
 Scale and rhizoids are present on the ventral side.
 Rhizoids are unicellular structures.
 Scales are present.
GEMMAE CUPS WITH GEMMAE
MARCHANTIA

14.  Adult gametophyte which emerges out from protonema contain
 Rhizoids
 Axis or stem &
 Phylloid or leaves.
 At the base of the stem branched, septate, multicellular
colourless rhizoids are present.
 Stem is erect and branches only once.
 Stem is covered with small simple, sessile leaves, which are
arranged in a spiral fashion.
 Leaf is green, ovate in shape.
 Main branch in young gametophyte behaves as male shoot and
side branches as female shoot.

15.  At the tip of male branch cluster of antheridia are present.
 Each antheridium is multicellular, massive stalk and club
shaped body.
 Jacket is made of single layer and contain numerous
chloroplasts when young.
 In the jacket cell, a cell present at the top “operculum” can be
easily differentiated which is responsible for the liberation of
sperms.

16.  Several archegonia are borne at the tip of the female shoot and
surrounded by leaves.
 Green, filament like paraphysis are intermingled with them.
 Each archegonium is present on a massive stalk.
 The archegonium can be differentiated into long twisted neck and
lower dilated one venter.
 Neck is made up of six longitudinal rows of cells and venter is
double layered.
 Neck contains 6-10 neck canal cells. Venter encloses one egg and
one venter canal cell
ARCHEGONIUM

17.  The mature sporangium consists of three parts
 Foot
 Seta
 Capsule.
 Foot is embedded in the tip of archegonial branch.
 Seta is very long and slender and bears sporogonium at its tip.
 Capsule is pear shaped and is covered by ruptured Calyptra and is
divided into 3 regions :
 Apophysis
 Theca &
 Operculum.
PERISTOME