B. Papp szerk.: Studia Botanica Hungarica 36. 2005 (Budapest, 2005)

Bercu, R.: Contributions to the anatomy of Asplenium ruta-muraria

Cross sections of the rhizome revealed that the epidermis consists of a single layer of cells uncovered by cuticle (Fig. 2B). Below the epidermis is the cortex consisting of large parenchyma cells. Remarkable is the abundance of starch grains in the cortical cells (Figs 2A, B). As OGURA (1938) and BlR (1957) have reported for Aspleniaceae species, the stele is a dictyostele composed of a variable number of meristeles (3-4) (in accordance with the number of foliar traces) (Fig. 2A), each surrounded by its own endodermis (starch sheath) and pericycle. The latter is composed of parenchyma cells regularly arranged in one row, (locally in two or even three rows). Each meristele is hadrocentric with a binary structure (metaxylem vessels towards the center, and protoxylem elements facing the pericycle) (Fig. 2C). The pith occupies the central area of the rhizome. Each meristele possesses a large packet of sclerenchyma cells facing the pith, with mechanical role (Fig. 2A). Fig. 2. Cross sections of the rhizome. - A: The stele (x47). - B: Portion with epidermis and cortex. C: A meristele stele (x 180): C = cortex, E = epidermis, GT - ground tissue, H = hypodermis, M = meristele, Mx = metaxylem, Pc = pericycle, Ph = phloem, Pi = pith, Px = protoxylem, Scl = sclerenchyma, SG = starch grains, SS = starch sheath. Orig.