Unidentified isolates of Cylindrocladium with
1–3-septate conidia and clavate vesicles were compared with
C. theae, C. colhounii var. colhounii, C. colhounii
var. macroconidiale, C. gracile, C. pteridis and
Calonectria gracilis. Ribosomal DNA (rDNA) of these isolates
were digested with the restriction enzymes EcoR I,
Hind III and Xho I, and Southern analysis performed
with the 6·3-kb rDNA repeat unit of Neurospora crassa
as DNA probe. Based on differences in general morphology, supported by
their rDNA restriction fragment length polymorphisms, isolates of all
species and varieties could be distinguished. Furthermore, the
Cylindrocladium anamorph of Calonectria gracilis was
shown to be distinct from Cylindrocladium pteridis and C.
gracile. The name Cylindrocladium pseudogracile sp.
nov. is, therefore, proposed for the undescribed anamorph of