Wetwood of Elms

Abstract

The investigation of wetwood reported in this paper is the outgrowth of studies of an unusual wilt observed on a large number of American elms in the Village of Hinsdale, Illinois, in July and August, 1939. As studies of the wilt progressed, it became apparent that this wilt was a secondary manifestation of disease intimately related to slime flux, a chronic bleeding at crotches and wounds, to abnormally high sap pressure in the trunk, and to wetwood, a water-soaked, darkly discolored condition of the heartwood. The investigation has shown that all of these conditions—wilting, high sap pressure and water-soaked, discolored wood—are phases of the wetwood disease, and that a bacterium, described as a new species, can cause wetwood in elms.