2-trees are defined recursively, starting from a single edge, by repeatedly erecting new triangles onto existing edges. These have been widely studied in connection with chordal graphs, series-parallel graphs, and isolated failure immune (IFI) networks.
A similar family, based on recursively erecting new \( K_{2,h} \) subgraphs onto existing edges, is shown to have analogous connections to chordal bipartite graphs, series-parallel graphs, and a notion motivated by IFI networks.