Stelar structure of aspleniaceae

The stelar morphology of adult and/or juvenile plants of 24 species of Aspleniaceae was examined. A radial dictyostele with two leaf-traces and a single root-trace at each leaf-gap is the most common type in the Aspleniaceae, whereas dorsiventral dictyosteles are present inAsplenium sect. Hymenasplenium andA. lepturus. The dorsiventral steles differ among species with regard to ontogenetical changes and root characteristics. Peculiar stelar structures are described forA. griffithianum andDiplora d'urvillaei. The typical single root-trace often divides to give rise to several or many branchlets in the hypodermal layer of the lowermost part of the petiole. A bud occasionally forms at the abaxial base of the stipe and is supplied by the bud-trace which actually departs from the point of divergence of the root-trace branchlets. A solenostelic bud-trace was observed inA. lepturus.