These are the club-shaped ascospores of Buergenerula spartinae, an ascomycete of the smooth-cordgrass leaf- decomposition system. The patches of leaf blades where this ascomycete resides are easily recognizable, because this species produces dark blackening of the leaf tissue above its ascomata. Its ascomata are three times larger than those of Phaeosphaeria spartinicola, filling the leaf blade from abaxial to adaxial surface. It may be that the blackening produced by B. spartinae is a competitive response to P. spartinicola; i.e., it may be fighting against invasion of its territory by producing defense chemicals. One hint that this might be true is that the blackened patches are avoided by grazing snails. Also, B. spartinae is an occupier of leaf sheaths, where P. spartinicola is never found, and in the leaf sheaths, B. spartinae does not produce black patches. B. spartinae produces identifiable structures (hyphopodia) on living grass parts, and so may be an endophyte in the living-grass tissue. It also produces tiny, bacterial-sized, vibrioid conidia (spermatia?), and may have a highly complex life history. It is very difficult to induce its ascospores to germinate, as opposed to the easily germinable ascospores of P. spartinicola and Mycosphaerella sp. 2. Lots of room for fun natural-history research here. See Newell SY, Wasowski J. 1995. Estuaries 18:241-249; Newell SY, Porter D. 1999. in Weinstein & Kreeger, Concepts and Controversies in Tidal Marsh Ecology, Kluwer.