XVI International Botanical Congess

Previous work (Kroken, et al., 1996, AJB 83:1241) has shown that certain high temperature, acid hydrolyzed remains of extant bryophytes are morphologically comparable to enigmatic fossils that have been attributed to earliest land plants. We isolated tissues of two species of the early divergent moss Polytrichum, hydrolyzed them, and examined the remains with light, fluorescence, and scanning electron microscopy. Hydrolyzed Polytrichum calyptra dissociated into smooth-walled, branched elements whose dimensions and morphology closely resemble ancient microfossils whose provenance is either unknown or hypothesized to be fungi. Quantitative measurements of resistant biomass were also made. These may be useful in estimating the relative potential contributions of early bryophyte-like land plants to carbon burial, and thus have paleobiogeochemical application.