Flora of an Illinois Coal Ball | Botanical Gazette: Vol 81, No 4
In the coal ball described were portions of plants that have hitherto been known from the Carboniferous of America only as impressions; they are Calamites, Sphenophyllum, Bothrodendron, and Lyginopteris. Only transverse sections of the steles of Calamites, Sphenophyllum, and Lyginopteris were found. Belonging to Bothrodendron are transverse sections of a stem tip, a megasporangium and ...