Evolutionary modification of the solenostele in ferns is believed to have resulted in a type of stele with two or more overlapping leaf gaps at any given level of the stem. This type of vascular cylinder is termed a dictyostele. When visualized in three dimensions, a stele of this type is a network of interconnected vascular strands.In some dictyosteles some of the parenchymatous regions are not truly leaf gaps, but interfascicular strips of parenchyma without a consistent relationship to the leaf trace system. This type of stele is termed a “dissected” dictyostele. A dictyostele, as