CALAMITALES THE EXTINCT LINES OF THE SPHENOPSIDA EVOLUTION
*Dr. Teena Agrawal
ABSTRACT
Pteridohpytes are plant with the sporophytic life of the pattern, prior to
the pteridophytes the life cycle pattern was the gametophytic(in
bryophytes), the sporophytic body is divided in to the roots, stem and
the leaves, reproduction occurs by the sporangium. Homospory and the
Heterospory is the prominent feature of the reproduction of the
pteridophytes. Archegonia and the antheridia are in reduces in sizes as
they are in the highest of the development of the bryophytes. All
pteridophytes have the heteromorphoic alternation of the generation.
Pteriodphytes have been divided in to the four of the classes. These are enlisted as the
psilophytopsida, Lycopsida, sphenopsida, pteropsida lines of the evolution, here in this
review articles we are presenting some of the features of the class sphenopsida, the extinct
orders calamitales, they were very abundant in the upper Devonian period and they forms
the large forest and ecosystem, in these plants Sporophytic body is divided in to the roots,
stem and leaves. The leaves are whorled in organization. The stele was protosteleic and
medullated. Sporangia was thick walled and the sporoangiphores are arranged in the thick
walled peltate sporagiophores. Antherozoids were multiflagellate, this group reached its
highest approximation in the upper carboniferous time period, they formed the giant forest in
the carboniferous with the lepidodendrales. Rapid declines occurs in the vegetation during the
Permian period.
Keywords: Sphenopsida, Multiflagealltes, Peltate sporangiophores, carboniferous s period, Heteromorphic alternation of the generation.
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