Denote by the variety of all completely regular semigroups with the unary operation of inversion within their maximal subgroups. Next let be the subvariety of in all of whose members Green's relation is a congruence. For an -subsemilattice of subvarieties of , we determine the lower ends of kernel, (left and right) trace, and core relations, and a basis of identities of its members with a few exceptions. The semilattice is presented by a diagram, and the results in a table.