1. Sphenopsida includes the living genus Equisetum and related extinct genera. They attained their maximum development in the Carboniferous period but are now nearly extinct except for Equisetum. 2. Equisetum is characterized by jointed, branched stems with whorls of small scales. It reproduces via spores borne in strobili. Spores germinate to form prothalli that bear archegonia and antheridia. 3. Ophioglossales is an order of ferns that includes the genus Ophioglossum. Ophioglossum has short, erect rhizomes bearing a single leaf. It reproduces via

1. COMPARATIVE MORPHOLOGY,STRUCTURE,ECOLOGY AND PHYLOGENY
OF THE GROUPS “SPHENOPSIDA,PTEROPSIDA”
PRESENTED BY…
ATHIRA.S

2. PTERIDOPHYTES
Vascular cryptogames
The name 1st introduced by Haeckel(1866)
Occupy a position in between bryophyts an gymnosperms
Plant body is sporophytic
Terrestrial,aquatic an few are xerophytic

3. PTERIDOPHYTES ARE CLASSIFYED INTO 4 GROUPS
Psilopsida
Lycopsida
Sphenopsida
Pteropsia

4. SPHENOPSIDA
Attained their maximum development in carboniferous flora
Only single genus equisetum is living
In carboniferons period grew to 25m
Spenopsida vegetation of the carboniferons period almost
extinct(expect equisetum)during unfavorable climate of the Permian
period
Equisetum is one of the oldest living genus of vascular plant in the
world today

5. FEATURES
Equisetum only living and 16 fossils
Sporophyte:root,stem&leaves
Stem:-articulated,branched,nodes&inter nodes,in some extinct forms
secondary thickening were observed
Leaves:-small scally arranged in nodes in whorls
Sporangia:-sporangia develops on sporangiophores & form strobilus
Spore:-members are homospores,extinct forms are heterospores
Antherozoids are multiflagellate
Embryo lacks suspensor

6. REPRODUCTION
Spores develop within sporangia and it borne on sporangiophore
Mature sporangia are sac-like attached to pellate disc of sporangiophore
Mature sporangia has 2 layered wall
Sporangium matures,the axes elongates,sporangiophores separate
Sporangium dries,shrink & sporangium reptures & spores releases
Spore germinates to a prothallus
Antheridia and archegonia are present
Protogynous
Archegonia has small neck and swellan base
Antherozoides are formed inside the antheridia
At maturity, neck canal cells &venter cells of archegonia desentegrates
Desentegrate mass attract antherozoides towards the neck
Only one antherozoid fuses with egg to form a diploid zygote

7. Sphenopsida is divided into 5 orders
1. Calamitales
2. Sphenophyllales
3. Equisetales
4. Hyeniales
5. pseudoborniales

8. SPHENOPHYLLALES
Fossil order of sphenopsida
Members appeared 1st in upper Devonian
The plant body is sporophytic
Stem divisible into nodes and inter nodes
Leaves simple wedge shaped and divided dichotomously into small
lobes
Plant has well organized strobilus
Sphenophyllales are divided into2
families,sphenophyllaceae,cheirostrobaceae

9. SPHENOPHYLLUM
Fossil genus
Appeared in upper Devonian&extinct in Triassic period
Stem were delicate and deviseble into nodes and inter nodes
Leaves whorle arrangement
6-18 leaves present in each nodes
Heterophyllous nature

10. PTEROPSIDA
Commonly known as ferns
Fossil plants
Sporophyte differentiated into root,stem&leaves
Leaves are large(megaphylls)compound stem is protostelic,siphonostelic or dictyostelic
Limited secondary growth
Sporangia are thick or thin walled
Homosporous or hetrosporous,borne in unmodified foliage or specialized fertile leaves
They are either terminal in leaf segment
Specialized structure sporocarp
Sporangia either are single or form sori or fues to form synangia
Antherozoids are multiflagllate

11. PETROPSIDA IS DEVIDED INTO 6 ORERS
Cladoxylales
Coenopteridales
Protopteridales
Marattiales
Ophiglossales
filicales

12. OPHIOGLOSSALES
Include 3 genera:-ophioglossum,botrychium and helminthostachys
Sporophytic plant body is herbaceons and rhizome,is short and flesh
Thick fleshy roots
Sporangia develop in the fertile axis
The sporangia are large and marginaly placed
Surronded by many-celled thick sporangial wall
A spore develops into subterranean mycorrhizic and tuberous
prothallus
Prothalli bear the sex organ

13. OPHIOGLOSSUM
Class : pteropsia
Subclass: eusporangiatae
Order : ophioglossales
Family : ophioglossaceae
Genus : ophioglossum
World wide distribution
Epiphytes,saprophyte,aquatic
Sporophytic plant body-short and errect
rhizome

14. Roots :- many thick adventitions roots on the rizhome
Roots hairs absent
Mycorrhizal in nature
Leaves:-borne in an irregular spiral on stem
Most species produce only one leaf in on growing season but in some
species 4-5 leaf are produce reticulate venation and stipule present

15. REPROUCTION
Spore bearing organs:-sporangia borne on a fertile spike
Spike has sterile stalk
Sporangia are embedded in either side of spike
Mature sporangium large fused with leaf
Spore mother cells functional and develop into
spore tetrad
Sporangial development is eusporngiate
Sporogenous cells function as for mother cells
Devide meiotically to form haploid spores
Dehiscence of sporangium through transverse cleft in
each sporangium
Spore germinate to prothali

16. Prothali has antheridia and archegonia
Antheridium development start from single superficial cell of the
gametophyte
1st periclinal division form outer jacket and inner androgonial cells
androgonial cells develops to androcyte mother cells& into antherozoids
Archegonium development start from single superficial archegonial initial
of the gametophyte
After further division archegonial develop
Developed archegonium has 4 celled neck,venter canal cell and egg
At the maturity,primary canal and venter canal cells disintegrate
The neck open the archegonium get ready for fertilization

17. Systematic position of ophiglossum
Lack any fossil record ,this order is grouped with ferns
Special type of plant body bearing single leaf of sterile & fertile segments
Vessels are present
Mycorrhizic roots
Root hairs absent

18. THANK YOU……..