Calamitean Cones and Their In Situ Spores from the Pennsylvanian Limnic Basins of the Czech Republic.

This paper describes the in situ spores of the Calamospora type, macerated from sixty-one specimens of calamitean cones belonging to sixteen species of genera, such as the Palaeostachya , Macrostachya , Calamostachys , and Huttonia from the Pennsylvanian Czech Republic period, specifically from the Moscovian/Kasimovian ages (i.e., Duckmantian-Stephanian). The in situ spores were compared to twenty dispersed species of Calamospora. The majority of spores were microspores; however, some cones yielded both micro- and megaspores. Morphological variations of the in situ spores, including the diameter, labrum, contact area, ontogenetic stages, and secondary folds of the exine, are described, including their importance for the classification of calamospores. The relationships of Elaterites , Pteroretis , Vestispora , and some monopseudosaccate spores are discussed. All Paleozoic Calamospora -producing parent plants are summarized.