Craterellus tubaeformis is a small to medium-sized forest mushroom that is fairly common in the Douglas-fir/western hemlock forests of the Pacific Northwestern United States and is most often associated with decayed coarse woody debris. In this study, the mycorrhizae of Craterellus tubaeformis in western Oregon is identified by DNA analysis using polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) typing, and the mantle morphology is described. Host associations with western hemlock, Douglas-fir, and Sitka spruce are identified using the same molecular techniques, with Craterellus tubaeformis most commonly associated with western hemlock. Differences in genetic sequences and host associations between western North America, eastern North America, and. Europe are presented, and the possibility that variants of Craterellus. tubaeformis from the different geographies might deserve their own species epithets is discussed. The dependency of Craterellus tubaeformis on late seral stands and abundance of coarse woody debris was quantified by surveying 64 plots in the Coast and Cascade ranges of western Oregon. Logistic regression showed that the odds of Craterellus tubaeformis occurrence increased with stand age and coarse woody debris (CWD) volumes, however it is often found in younger stands. The likelihood of Craterellus tubaeformis occurrence in a stand was highly correlated to the presence of western hemlock. Linear regression analysis showed no significant relationships between stand age, CWD volume, slope, elevation, or aspect on Craterellus tubaeformis biomass productivity, though well-decayed CWD was the substrate for 88% of the collected biomass. The presence of Hydnuin spp. was found to be a highly significant indicator for the presence of Craterellus tubaeformis
