The focus of this paper is on the public communication required for generating a maximal-rate secret key (SK) within the multiterminal source model of Csiszár and Narayan. Building on the prior work of Tyagi for the twoterminal scenario, we derive a lower bound on the communication complexity, RSK, defined to be the minimum rate of public communication needed to generate a maximal-rate SK. It is well known that the minimum rate of communication for omniscience, denoted by RCO, is an upper bound on RSK. For the class of pairwise independent network (PIN) models defined on uniform hypergraphs, we show that a certain "Type S" condition, which is verifiable in polynomial time, guarantees that our lower bound on RSK meets the RCO upper bound. Thus, PIN models satisfying our condition are RSK-maximal, meaning that the upper bound RSK ≤ RCO holds with equality. This allows us to explicitly evaluate RSK for such PIN models. We also give several examples of PIN models that satisfy our Type S condition. Finally, we prove that for an arbitrary multiterminal source model, a stricter version of our Type S condition implies that communication from all terminals ("omnivocality") is needed for establishing a SK of maximum rate.For three-terminal source models, the converse is also true: omnivocality is needed for generating a maximal-rate SK only if the strict Type S condition is satisfied. Counterexamples exist that show that the converse is not true in general for source models with four or more terminals.