3. Occurrence
It grows on moist rocks or occures on shaded sides of tree
trunks. It forms dense mats closely covering the
substratum. Some are aquatic and grow in cool waters.
4. EXTERNAL
● Greenish, leafy plant body
● Consist of branched central axis
● Two kinds of leaves- Dorsal and ventral arranged in three rows
● Ventral leaves are small, simple and reduced. Arranged in lower
side of the stem.
5.
6. ● Each dorsal leaf is bilobed- divided into two lobes.
● Many smooth-walled rhizoids arise from the base of ventral leaves.
7. STEM
● Young stem consist of uniform tissue of parenchyma cells ( no tissue
differentiation)
● In old Stem shows little more internal differentiation of tissues.
● The axis shows two parts, i.e., outer cortex and the central medulla.
● The outer cortical cells are small and thick-walled. The inner medullary cells
are large and thin-walled.
ANATOMY
9. Antheridia
● Develop on short lateral braches.
● Male branch is right angle
● Globose with long stalk
● Globose body have wall which is one cell thick(cholroplast)
● Androcytes inside the wall
● Spirally coiled biflagellate sperm
10.
11.
12. Archegonia
● On side branches of female plants.
● Acrogynous - Apical cell forms archegonia
● Archegonia occur in terminal cluster
13. ● Each archegonium is more or less a cylindrical object
with the Venter and neck.
● Neck consist of five vertical rows of neck cells
● Neck canal contains 6-8 neck canal cells.
● Venter contains egg and venter canal cell
14. ● The neck canal cells and the venter canal cells of mature archegonia
degenerate. They form mucilage-like substance
● It exerts pressure and burst the neck cells. The mucilaginous fluid
oozes out of ruptured neck and attracts the sperms. A large number
of sperms collect near the neck. But only one of them passes down
● Fertilization takes place, zygote is formed.
FERTILIZATION
15. Sporophyte
● Sporogonium develops from the diploid zygote by repeated
mitotic divisions, and differentiation of cells
● Sporogonium at maturity differentiated in to foot, seta and
capsule
Foot:Enlarged base of the seta
Seta:Carries sperical capsule at it's top
Capsule:Within the capsule wall are the spores.
16.
17. ● Sporogpnium lives parasitically upon the parent
gametophyte.
● Within the Capsule wall is sporogenous tissue. Which
gets differentiated into spore mother cells.
● Spore mother cell undergo meiosis to produce four
haploid spores.
● The spore, on germination produce a distinct
Protonema stage.
