We construct the BPS quivers with superpotential for the 4d N=2 gauge theories with non-simply laced Lie groups (B_n, C_n, F_4 and G_2). The construction is inspired by the BIKMSV geometric engineering of these gauge groups as non-split singular elliptic fibrations. From the categorical viewpoint of arXiv:1203.6743, the fibration of the light category L(g) over the (degenerate) Gaiotto curve has a monodromy given by the action of the outer automorphism of the corresponding unfolded Lie algebra.

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... In view of the Katz--Vafa 'matter from geometry' mechanism, the monodromic idea may be extended to the construction of (Q, W) for SYM coupled to higher matter representations. This is done through a construction we call specialization.