SUMMARY1Glomerella phacidiomorpha(Ces.) Pet. has been found to be the cause of a disease ofPhormium tenaxin England. This is the first record of the fungus in Britain.2The fungus is only weakly parasitic, and is of danger only to plants of lowered vitality.3The imperfect fungusColletotrichum rhodocyclum(Mont.) Pet. is shown to be a conidial stage ofGlomerella phacidiomorpha.I wish to express my indebtedness to Mrs N. L. Alcock, Plant Pathologist to the Department of Agriculture for Scotland, who supplied the material ofPhormium tenax,and to Dr M. Wilson, Mycology Department, University of Edinburgh, who supervised the work.