To Study and identify the supplied speciment of Selaginella

Aim of the experiment :-   To the study and identify the supplied speciment. (Bsc Botany Practical)

Under any Recognice University like Dibrugarh University,Gauhati University,Bsc CBCS,Botany Notes,Bsc Practical

Requirement :- Slide, coverslide ,Needle ,sefranin,petridish,speciemnt and Microscope.

Procedure :-A few portion of the supplied speciement is taken on a clean slide,stained with sefranine and observecd under the compound microscope.

Vegetative Structure : 

 On the basis of the general structure of the stem and groups of sub -genera Homoephyllum and Heterophyllum.The examples of sub-genus Homoephyllum are S.pygmaen.S.speiinus .S ruptries and others these species passes erect stems and the spirally arranged leaves of the same size covering the stems.The sub-genus Heterophyllum comprises majority of the species ,the examples are S.Kraussiana ,S.Lepidophylla and many othhers they passes prostrate stems ,shorts erect branches and the dimophic leaves.

Stem and leaves

(Bsc Botrany)In each case the stem is converted over with four rows of leaves .Sub-genus Heterogenus -Heterophyllum.The species to sub-genus Heterophyllum passes prastrate stemm,short erecyt branches aand the differnent  size (dimorphic)leaves .The prastrate stem is dorsiventral.

Internal Structure :

T.S of stem the epidermis is the superdicial layer of the stem that consist of prasenchymatouse cutiniized cell.The stems of most species  passes stretched endodermal cells having large intracellularr among them.

Reproductive Structure :

Spore producing organs  strobilus or spike : The spore producing structure develop at the apces of the branches they are called strobillus or spikes.The strobillus is a compact sttructure or spikes.

Identification and systematic  position:

(i)Presence of independent gametophytes and sporophytes,Sporophytes passes well developed vascullar strands.

(ii)Sporophyte differantiated into stem ,roots and leaves,microphyllous with a single veins.

(iii)Ligule present ,Rhizophares present on the stem,Heterosporanigium sporangia,Similasr oor dimorphic leaves...order ..Selaginnela.

(iv)Stem herbaccocus ,creepiing or erect ...Family ...sellaginella.

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