This note originated as a mathematical jest due to the resemblance between the standard notation T ', for the result of raking the leaves of a tree T, and the prime-notation for the derivative of a function x. It was then natural to define the integral of a tree as the reverse procedure, i.e., so that the integral of a tree T is a tree S such that S '=T. Then a reasonable analog to the constant of integration suggested itself, as well as a natural notion of partial derivative. This in turn led to generalizations of the two binary operations, the corona and the composition of two graphs. Finally it was noted that the iterated integral of the trivial graph Ki, consisting of just one node, results in the family of broadcast rees which play a role in the theory of parallel computing and bear a structural resemblance to hypercubes.