A COMPARISON OF GENERIC CONCEPTS IN CALONECTRIA AND NECTRIA WITH ANAMORPHS IN CYLINDROCLADIUM AND CYLINDROCLADIELLA

Cylindrocladium and Cylindrocladiella have been considered as a single genus by numerous authors. We dispute this fact because Cylindrocladi um has Calonectria teleomorphs, whereas Cylindrocladiella has Nectria teleomorphs. In addition to the differences in their teleomorph states , the anamorphs are also morphologically distinct and probably not clo sely related. The tendency to amalgamate Cylindrocladium and Cylindroc ladiella has chiefly resulted from interpreting the stipitate conidiop hores as a unifying characteristic. It must, however, be expected that similar themes in morphology will result from adaptation to analogous environments, and therefore convergence. We conclude that separation of tara based on single characteristics should be avoided. Rather, con sideration of as many characteristics of the holomorph as possible is essential. In the fungi discussed here, teleomorph characteristics ten d to be conserved and uniform, whereas anamorphs are more variable, of ten providing excellent characters for species delimitation.