This is a typical deposit of ascospores from a
standing-decaying leaf blade of smooth cordgrass (Spartina
alterniflora). A wetted decaying blade was placed a few
millimeters over a coverslip and the ascomycetes within the
blade expelled ascospores onto the coverslip at a rate of
hundreds per square centimeter per hour. This view is
of the coverslip at the microscope (for scale, the dark, 4-celled
spores [P. spartinicola] are about 35 microns long). The
smaller, colorless spores are of Mycosphaerella sp.2. These
two species are nearly always found thoroughly mixed in the
leaf-decay community -- they may be mutualists, perhaps digesting
different portions of the cordgrass. See Newell, SY, 2001, Limnol.
Oceanogr. 46:573-583 -- Web:
http://www.aslo.org/lo/toc/vol_46/issue_3/0573.pdf