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Sordaria fimicola

Note the clumps of ascospores at different levels inside the flask-shaped ascoma (=perithecium).  Each clump is an ascus containing 8 ascospores.  You are viewing the asci through the pseudoparenchymatous wall of the fruitbody and the ascus walls are too delicate to be resolved.  The asci are guided by the phtotropic neck to shoot their spores towards the direction of incident light and away from their coprophilous substrate.

Sordaria fimicola  is another of the common dung-loving (=coprophilous) fungi. Sordaria belongs in the Sphaeriales (=order) of the Ascomycota (=Division).   It is often used in introductory mycology labs because it has a number of  useful and/or interesting attributes e.g. 

1.  It grows well on nutrient agar in culture (e.g. malt extract agar, potato dextrose agar) and can grow and produce mature fruitbodies in about a week.

2. The neck of the fruitbody (= a perithecial type ascoma) is phototropic and bends in the direction of  theincident light.   

3. Sordaria is naturally auxotrophic (= nutritionally dependent).  It requires biotin for growth and will grow on minimal medium (see paragraph below) plus biotin but will not fruit unless thiamine is available.   Biotin and thiamine belong to the Vitamin B complex.  Sordaria, therefore, is dependent on external sources of certain vitamins (as are we) and must get these from its environment.      

4.  Sordaria shoots off its ascospores towards a light source thus the direction can be controlled and the distance shot can be estimated with reasonable accuracy.

Note:    All fungi need an 'organic carbon' energy source.  Apart from this requirement many fungi, such as Aspergillus and Penicillium, are otherwise  nutritionally independent and can synthesise all the vitamins etc essential to growth and reproduction.  Thus, Aspergillus can grow and fruit on a medium containing only inorganic salts and a carbon energy source (e.g. sucrose). This is called a MINIMAL MEDIUM (=MM).