Contrary to initial views, there are two major species involved in the production of high concentrations of dark ascomata (ascomycetous sexual structures) in standing-decaying leaf blades of smooth cordgrass. Phaeosphaeria spartinicola was the one believed to perform the "black-peppering" on its own, but it has been discovered that Mycosphaerella sp. 2 (of Kohlmeyer & Kohlmeyer) is virtually always intermingled with P. spartinicola. An ascospore of Mycosphaerella sp. 2 is shown in this image: it is the clear and much smaller (about 17 µm long), 2-celled spore in between the two dark-brown spores of P. spartinicola. The ascospores in this image were photographed on an ascospore-capture target (capturing spores shot from blades collected in the marsh); they have germinated to form a web of hyphae. The putative partnership between P. spartinicola and the microalga Pseudendoclonium submarinum may be a 3-way deal, and the lignocellulose-lysing mycelium found beneath the "black-peppering" is likely to be of both P. spartinicola and Mycosphaerella sp. 2. My2 is still taxonomically adrift -- it needs a published name! See Newell, 2001, Botanica Marina 44:277-285; Newell & Porter, 2000, pp. 159-185, in Weinstein & Kreeger, Concepts and Controversies in Tidal Marsh Ecology, Kluwer.