FUNGI IN WETLAND ENVIRONMENTS: OCCURRENCE ON AND ALTERATION OF LEAVES AND WOOD FROM THE ‘BOUDREAUX BEND’ BED

The informally designated ‘Boudreaux Bend’ Beds are a series of blue-grey to dark brown silty clay deposits presently exposed in the banks of numerous creeks in the Morehead and adjacent quadrangles of Kentucky. The beds rest conformably on imbricated coarse pebble conglomerates and contain scattered stringers of imbricated fine pebbles and coarse sand. They are overlain by either soil horizons or by a distinctive bed of pale yellow silt, colloquially referred to as the ‘Mystery Unit.’ The beds contain abundant plant remains, including leaves, seeds, wood, and charcoal, and are approaching lignitic in areas. Leaves were separated from the matrix using a solution of 25% sodium hexametaphosphate and cleared with KOH prior to dehydration and mounting in PVA for transmitted light examination and epoxy for organic petrography. Wood and charcoal were manually removed from the matrix and sectioned to reveal fresh surfaces before mounting in epoxy for organic petrography. Both leaves and wood support a diverse fungal community, with forms known to represent both parasites and saprophytes. Epiphyllous fungal forms similar to those observed on leaves from Clarkia (Miocene) and the Claiborne Group (middle Eocene) are present. Leaves generally display intense lemon-yellow fluorescence in the absence of fungi; where fungi are present, fluorescence is reduced. Wood samples are generally well preserved, although gelification has begun to occur, especially in the outer portions of the wood. Fungi in wood occur as both hyphae but also as spores and sclerotia. These forms are similar to those observed in Miocene coals and modern decaying wood. Wood fluorescence is variable, but generally yellow and, like the leaves, is less intense where the wood has been impacted by fungi.