Template:POTD/2010-02-24
The asci of a Morchella elata morel mushroom, as seen with phase contrast microscopy (the total field of view is 218 × 164 µm). An ascus is a capsule containing the sexual ascospores produced in ascomycete fungi. The shape of the ascus is important for species classification within the Ascomycota phylum.Photo credit: Peter G Werner