The author draws attention to the ways in which commodity chains take shape in the intersections between different natural – cultural ecologies. It is suggested that a focus on the diverse ways that people involved in commodity chains relate to these ecologies reveals not only the links but also the disarticulations through which commodity relations take shape. To develop this perspective, the author focuses on the trade in ‘matsutake,' a variety of related species of wild mushrooms that are consumed primarily as a gourmet luxury item in Japan. Matsutake have never been successfully cultivated, and during the 1970s and 80s, as a growing market for luxuries in Japan coincided with a decline in domestic production, Japan began importing increasing amounts of them. The author first considers scientific discussions about the contingencies and uncertainties that relationships involving fungi, trees, people, nematodes, beetles, and weather create in different matsutake regions. Discussion then turns to the some of the different ways that matsutake pickers in rural Nagano and matsutake traders in Tokyo make sense of these uncertainties by characterizing matsutake ecologies as, respectively, ecologies of vulnerability and ecologies of negotiation. By attending to the conflicting ways that people make sense of human – nonhuman relations in matsutake exchange, the author demonstrates that commodity chains do not occur through smoothly articulated chains, networks, or circuits: rather, they involve processes in which variously situated ecologies collide across relations of geographical and cultural difference.