Elektronenmikrospopie der sporodermis von megasporen der gattung selaginella (Pteridophyta)

Abstract

Recent megaspores of Selaginella galeottii, S. selaginoides, and S. usta have been investigated in ultrathin sections with the aid of an electron microscope. The sporoderm is composed of three layers, which are named intine, exine, and perine. A mesine does not exist. The intine shows a lamellar fine structure. The exine consists of a remarkable thin and quite homogeneous membrane, which until now has been regarded as the mesine or endexine. By far the largest part of the sporoderm is formed by the perine, which shows a monozonal (S. selaginoides), bizonal (S. usta), or trizonal (S. galeottii) kind of formation. The fine structure of the perine is composed of a network of threads and looks different from species to species. In addition to this the sculpture of the spore surface is formed by the perine alone. Therefore, it is possible to use the fine structure of the perine as well as the ornamentation of the spore surface for taxonomical purposes. © 1970.