The standing-dead leaf blades of smooth-cordgrass (Spartina alterniflora) have ascospores of Phaeosphaeria spartinicola in place by the time they die. The ascospores germinate and pervade the dead blades, digest much of the blade material, and convert part of it into ascomata, the exteriorly melanized spheroids in which the sexual spores are generated. The black structures seen here are the ascomata of P. spartinicola mixed with those of Mycosphaerella sp. 2. The spheroidal ascomata (about 75-150 µm diam) are often clustered together so closely that they just look like irregular black patches from surface view -- one has to dig them out with a needle to get a good look at them. If you look closely at this image, you will see a few little bright, moist-looking spots in the black areas. These are the ostioles of mature ascomata, the openings through which the ascospores are explosively expelled. The shininess at the ostioles is caused by the tips of the asci, which have pushed through into the air, in preparation for firing away their ascospores. See Newell & Wasowski, 1995, Estuaries 18:241-249; Newell & Porter, 2000, pp. 159-185, in Weinstein & Kreeger, Concepts and Controversies in Tidal Marsh Ecology, Kluwer.