B. Papp szerk.: Studia Botanica Hungarica 32. 2001 (Budapest, 2001)

Bercu, R.; Péterfi, St.: Anatomical aspects of the leaf blade in fern Polystichum setiferum (Forsk.) Woynar

RESULTS AND DISCUSSION Cross sections of the pinnule revealed that the upper epidermis consists of one layer of isodiametric cells with chloroplasts, covered by cuticle. Right to the main vein, the upper epidermal cells are smaller and form a median ditch (Fig. 1). The chlorophyllaceous mesophyll consists of several layers of large parenchymatous cells. Some of them are branched and septate, large intercellular spaces are located among them, especially to the lower epidermis. It can be seen a slight differentiation tendency of the mesophyll into palisade and spongy tissue, but it remains still a homogeneous one (Fig. 1). Many authors consider that the mesophyll of ferns blade is homogeneous (OGURA 1938, RAVEN et al. 1992, STERN 1994). In the leaf blade of some species of ferns, such as Dryopteris filix-mas, Athyrium filix-femina, Asplenium septentrionale (BERCU 1998, 2001) also exist an arrangement tendency of the mesophyll cells into a palisade tissue to the upper epidermis and a spongy one, to the lower epidermis. Fig. 1. Polystichum setiferum (Forsk.) Woynar. Cross section of the leaf blade: Ct = cuticle, IS = intercellular space, LE = lower epidermis, M = mesophyll, Mx = metaxylem, MV = middle vein, Ph = phloem, Px = protoxylem, S = stoma, SS = sclerenchymatous sheath, Sc = sclerenchyma, UE = upper epidermis. x375. Orig. Studio hot. hung. 32, 2001