Glossopteris Flora of India
Glossopteris:-
> Fossils of the gymnosperm Glossopteris (dark green) found in all of the southern continents .
> Glossopteris (Ancient Greek: glossa, meaning "tongue", because the leaves were tongue-shaped).
> The name glossopteris is first used by Brongniart.
Species:-
i. G.angustifolia
ii. G. brasiliensis
iii. G. browniana
iv. G. communis
v. G. indica
vi. G. occidentalis
Distribution:-
> Gondwana land was greatest ice age.
> This condition extended from upper carboniferous to lower permian period.
> Gondwana land flora is also called glossopteris flora.
> Gondwanaland system are of 3 types.
a. Lower gondwana system
b. Middle gondwana system
c. Upper gondwana system
a. Lower gondwana system:- It was the luxuriant growth period of gymnosperm. It include several several speciesof Gangamopteris, Glossopteris with Vertebraria and Gondwanadium
b. Middle gondwana system:- Glossopteris genera, glossopteris with vertebraria, gamopteris are included in this system.
c. Upper gondwana system:- Glossopteris genera glossopteris with vertebraria are seen in this system.
- Leaves - tongue like with reticulate venation.
- Has a central mid rib, lateral veins are arise from the mid rib and these extended to the margin.
- Dorsiventral.
- Seeds are borne on the sides of variably branched or fused structures.
- Microsporangia are borne on the tip of filaments ,containing large no. of pollen.
- Seeds and pollen bearing organs were partially fused to leaves or positioned in the axils of leaves.
- Seed bearing structures are remain within the megasporophyll.
- It is not clear that glossopteris is monoecious or dioecious.
- They had unusual roots called vertebraria.