Detached and coalified prepollen organs with huge monolete grains are reported for the first time from the Canadian Sydney Coalfield of Pennsylvanian age. Besides regarding these organs as Dolerotheca-like, the putative question is which medullosalean seed fern produced these organs? We investigated for the first time the physicochemistry of the prepollen to determine characteristic behavior under oxidative conditions, reporting results from solid- and liquid states infrared spectroscopy, liquid H-1 magnetic resonance, high precision liquid and pyrolytic-gas chromatography, and mass/charge ratios. The organs were tripartite, campanulate (bell-shaped) with lobate margins ca. 20 mm in diameter and ca. 30 mm long, and contained hundreds of elongate sporangia that were up to 8 mm long and filled with huge up to 833 ism long but probably juvenile Monoletes prepollen. These grains were covered by an acellular sporangial layer, which in turn, was covered by a cuticle bearing the imprint of near-isodiametric cells. The principal evidence for linking the Dolerotheca-like structure to foliar Alethopteris pseudograndinioides is shared occurrences of papillate cyclocytic stomata and trichomes, and the physical association of the alethopterid foliage and the prepollen organs. The physicochemical results point to diagenetic influence on the surface morphology and taxonomic parameters, refractory nature of the prepollen (as with extant pollen), and their aliphatic characteristics that are different from the aromatic extant pollen.