Black stain root disease (BSRD) is a vascular wilt disease of conifers caused by three varieties of the native, insect-vectored fungal pathogen, Leptographium wageneri (L. wageneri var. wageneri, L. wageneri var. ponderosum, and L. wageneri var. pseudotsugae). Although morphological, physiological, and ecological characteristics differ among the three varieties of L....