A multicast scheme for scheduling a root flow in an ATM environment. A buffer system including an index memory is operable to contain a plurality of leaf flow index values associated with the leaves and a root flow index associated with the root flow from the ingress interface. A pointer memory is provided wherein a plurality of circularly-linked pointers are indexed from the leaf and root flows. A cell memory is provided with a plurality of cell memory locations to which the linked pointers point. Root flow cells in the ATM environment are stored in the cell memory locations based on the root flow index. When a particular flow becomes eligible for scheduling, a copy of a root cell is obtained for emission, the root cell being located in a cell memory location that is pointed to by a linked pointer, to which the particular leaf flow is indexed.