An outcrop of the Duquesne Coal (Conemaugh Cyclothem) has the only significant occurrence of coal balls in Upper Pennsylvanian (Stephanian B equivalent) sediments of the Appalachian Basin. Excellent preservation of plant debris within autochthonous pear has permitted a more refined reconstruction of the source plant community than reported in published studies of other coals. Coal balls were quantitatively sampled for whole-plant species and mineralogical content. Shoot-root ratios were extremely high compared with values reported for other coals. The samples were analyzed using cluster analyses and non-metric multidimensional scaling (MDS) in order to differentiate microhabitats and stages of ecological succession within the general flora. Cluster analysis produced 5 stable clusters, which agreed with the sequence of ecological succession as determined in a previous study, and with microhabitat differentiation in contemporaneous seral stages. Three dimensions of the MDS analysis provided the best fit to the data. The dimensions are interpreted as representing: (1) ecological time or succession; (2) increasing dominance of Psaronius tree ferns in the plant community; and (3) an increase in microtopological variation (probably hummock formation). The initial stages of succession (oldest layers of permineralized peat) are characterized by aerial debris from Mesoxylon, Sigillaria and Calamites, followed by an assemblage dominated by Chaloneria. This was succeeded by more species diverse assemblage, dominated by Neuropteris seed ferns and Psaronius tree ferns, with numerous subcanopy plants, including lianas, epiphytes and ground herbs. Late seral stages (youngest layers of permineralized peat) were dominated by Psaronius tree ferns.