A PENNSYLVANIAN CALAMITEAN CONE WITH ELATERITES TRIFERENS SPORES

In 1943 L. R. Wilson described some scattered elater-bearing spores found in a Middle Pennsylvanian coal ball from What Cheer, Iowa, as Elaterites triferens. The spores, averaging 60 μ in diameter, with a trilete scar on the proximal surface and three conspicuous elaters attached to their distal surface, have now been found in a fragment of a cone from the same locality. The cone is similar to Calamostachys in having whorls of sporangiophores, each with four adaxial sporangia, and some secondary xylem at the nodes, but it possibly differs in lacking sterile bracts.