Abstract. The paper develops a rather unexpected parallel to the multivariate Matsumoto-Yor (MY) property on trees considered in [19]. The parallel concerns a multivariate version of the Kummer distribution, which is generated by a tree. Given a tree of size p, we direct it by choosing a vertex, say r, as a root. With such a directed tree we associate a map Φr. For a random vector S having a p-variate tree-Kummer distribution and any root r, we prove that Φr(S) has independent components. Moreover, we show that if S is a random vector in (0, ∞) p and for any leaf r of the tree the components of Φr(S) are independent, then one of these components has a Gamma distribution and the remaining p − 1 components have Kummer distributions. Our point of departure is a relatively simple independence property due to [10]. It states that if X and Y are independent random variables having Kummer and Gamma distributions (with suitably related parameters) and T : (0, ∞) 2 → (0, ∞) 2 is the involution defined by T (x, y) = (y/(1 + x), x + xy/(1 + x)), then the random vector T (X, Y ) has also independent components with Kummer and gamma distributions. By a method inspired by a proof of a similar result for the MY property, we show that this independence property characterizes the gamma and Kummer laws.