THE RHIZOID-INITIAL FIELD - A VALUABLE TAXONOMIC CHARACTER IN SPECIESOF THE GENUS CALYPOGEIA RADDI (HEPATICAE, JUNGERMANNIALES)

The anatomical structure of the underleaf base in the European species of the genus Calypogeia has been studied in longitudinal stem section s. This base consists of two largely independent parts: the one-layere d rhizoid-initial field and the underleaf base proper. The distinct di fferences between particular species were observed and a key for the C entral European species of Calypogeia has been constructed on that bas is. As these differences were stable in culture experiments and were o bserved also in mixed colonies in the field, we conclude that the stru cture of the underleaf base is here, most probably, genetically fixed.