COMPARATIVE-STUDY OF THE ASCI AND THE ASCOSPORES OF SOME MORCHELLA (GENUS MORCHELLA, ASCOMYCETES)

Asci and ascospores are compared in the following species of Morehella : M. conica (Pers.) Boud., M. deliciosa Fr., M, elata (Fr.) Boud., M. esculenta (L.: Fr.) Pers., M. eximia Boud., M. intermedia Boud., M. p seudoumbrina Ict., M. rotunda (Pers.) Boud., M, vulgaris(Pers.) Boud. With the light microscope the great homogeneity of the genus is confir med : operculate asci, unicellular hyaline ascospores with polar oil d roplets. The scanning electron microscope reveals as a permanent featu re an ornamentation of the ascospore wall, which develops from faint r ibs to more salient ridges or even alveolate depressions. These featur es do not display enough differences to be used as systematic criteria within the genus Morchella; other criteria ale briefly discussed.