When we stopped in the woods by the decaying long we saw a number of different saprophytic fungi.  Among them was this tan to light brown colored ascomycete (sac or cup fungus), a member of the Division Eumycota (some systematists classify the sac fungi in a separate division, the Ascomycota).  As we learned in class, this ascomycete is readily confused at first glance in the field with some members of the Myxomycota, the slime molds.  Although many sac fungi produce their spores in cup-shaped structures (hence the name cup fungi), the sac fungus on the log produces its spores in the tiny, closed, spherical structures you saw in the lab. 

                                         The small, tan, spherical structures on the decaying log (left) contain the spores of this fungus.  When crushed
                                         and viewed with the microscope (right), groups of spores (ascospores) can be seen as dark lines.  X100
 

                                         When the groups of spores are enlarged, both immature (left) and mature (right) ascospores can be seen.  Note
                                          that each group of spores is contained in a transparent sac (ascus) and there are 8 spores in each ascus.  X450

                                                                                                                                        © 2001 Joseph R. Thomasson