These are pieces of naturally-decaying blades of smooth cordgrass (Spartina alterniflora) from saltmarshes along the east coast of the USA, from Massachusetts (MA) to Florida (FL Gulf coast), all collected in autumn. It was once proposed that smooth-cordgrass blades from northern latitudes would exhibit less fungal activity than those from southerly latitudes. This may be true, since shoots are often shoved onto the sediment by snow and ice, and sheared off by ice. But much of the shoot material decays before ice and snow can impact the system, and as can be seen here, fungal activity in the northern samples is obvious from the blackened and "black-peppered" blades caused by production of fungal sexual structures (see link 1 and link 2). My partners and I, in a study of latitudinal variability of activity of ascomycetes in the decaying-cordgrass system, have found no south-to-north pattern in standing crops of living-fungal mass or in rates of fungal membrane synthesis. One of the highest rates of fungal production was found for samples from Wells Reserve in Maine. See Newell & Porter, 2000, pp. 159-185 in Weinstein & Kreeger, Concepts and Controversies in Tidal Marsh Ecology, Kluwer.