Abstract
The thallus ofThorea ramosissima was studied electron microscopically. The cells of the medulla, the cortex and the assimilatory hairs differ not only in size and number of plastids and their equipment with thylakoids but also in cell wall structure, the number of mitochondria and the activity of the Golgi apparatus, with dictyosomes transforming complete cisternae into Golgi vesicles with mucilaginous contents in the outer region of the cortex. The pit connections have plugs with a distinct plate—like (not dome-like) outer cap layer. BecauseT. riekei was reported to have dome-like outer cap layers and because this character was the main reason to place theThoreaceae into theBatrachospermales (Pueschel & Cole 1982),T. riekei was reinvestigated, too. A distinct outer cap could not be detected. The reliability of pit plug structure as a taxonomic character and the taxonomic position ofThorea is discussed.
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Schnepf, E. Electron microscopical studies ofThorea ramosissima (Thoreaceae, Rhodophyta): Taxonomic implications ofThorea pit plug ultrastructure. Pl Syst Evol 181, 233–244 (1992). https://doi.org/10.1007/BF00937447
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DOI: https://doi.org/10.1007/BF00937447