SCYTONEMA​

CLASSIFICATION OF SCYTONEMA

Sub-division :- Algae

Class :- Myxophyceae

Order :- Nostocales

Family :- Scytonemataceae

Genus :- Scytonema

The genus Scytonema is usually found in sub-aerial habitats such as damp walls, brick-work, bark of the trees, etc. Filaments are interwoven to form a felt-like mass of considerable extent. Few species grow best on damp soil and others on the dripping surfaces of rocky cliffs.

SCYTONEMA

EXTERNAL FEATURES OF THALLUS​

COMMENTS :-

  • Filaments occur singly. The trichomes are enveloped in a sheath. 
  • Filaments show false branching, branches being single or geminate (in pairs). 
  • The trichomes are of the same diameter throughout its length. 
  • The trichome is covered by an individual sheath which is firm and either hyaline or coloured. It may be homogeneous or lamellated.
  • Heterocysts occupy intercalary position. It may be either single, in twos or threes. These are approximately of the same size as those of vegetative cells. Lateral branches are generally produced in between heterocysts. 
  • Heterocysts show two shining granules, one each in contact with the cells on either side. It is pale yellow in colour and contents are homogenous.
  • Cell structure is typically cyanophycean. Central part known as centroplasm is enclosed by peripheral pigmented chromatoplasm. The centroplasm has genetic material in the form of DNA. The chromatoplasm has scattered pigments and cyanophycean granules.
Scytonema. A part of thallus to show false branching.

STUDY OF HORMOGONIA

COMMENTS :-

  • Sexual reproduction is absent.
  • Akinetes are asexual reproductive bodies. These are of rare occurrence. 
  • Hormogones are found very commonly. They are solitary and terminal. 
  • Hormogone is a spherical structure that is covered by a thick mucilaginous envelope.
SCYTONEMA

IDENTIFICATION OF SCYTONEMA​

  • Sub-division Algae
    1. Thallus simple,
    2. Chlorophyll present.
    3. Cell walls of cellulose.  
  • Class Myxophyceae
    1. Chromatophore not organised, pigments diffused, blue-green.
    2. Photosynthetic reserve cyanophycean starch.
    3. True nucleus absent.
    4. Sexual reproduction absent.
  • Order Nostocales
    1.  Thallus with trichomes, unbranched, or with false branching.
    2. Hormogones, heterocysts, exospores and endospores generally present.  
  • Family Scytonemataceae
    1.  Trichomes uniseriate, without marked attenuation.
    2. Filaments always free, with false branching.
    3. Sheath firm, enclosing one or more trichomes.
  • GenusScytonema
    1. Filaments with heterocysts.
    2. One trichome within a sheath.
    3. False branching present.
    4. Branches arising in pairs.

This Post Has 6 Comments

  1. folder

    Αmazing things here. I am very happy tօ see youг article.
    Tһanks so much and I’m looking fоrward to contact you.

  2. Steve

    Gοod write-up. I certаinly аppreciate this
    site. Continue the good work!

  3. patrick

    Wow! Ꭺftеr all I got a Ƅlog from where I be able to really obtain useful facts regarding my study and knowledge.

  4. Robert

    Y᧐ur mode of еxplaining еverything in this paragraph іs аctually goօd, every
    one be capable of simply be aware of it, Thankѕ a lot.

  5. Fiona

    Ѕpot on with this write-up, I seriously believe thіs amazing site needs far more attention. I’ll probably be back again to see more, thanks for the advice!

  6. Andrew

    This sitе defіnitely has all of the infoгmatіon I needed about this subject and dіdn’t know wһo to
    ask.

Leave a Reply