  It is a conventional wisdom that the helical edge states of quantum spin Hall
(QSH) insulator are particularly stable due to the topological protection of
time-reversal symmetry. Here, we report the first experimental observation of
an edge-dependent quantum (pseudo-)spin Hall effect by employing two Kekule
electric circuits with molecule-zigzag and partially-bearded edges, where the
chirality of the circulating current in the unit cell mimics the electron spin.
We observe a helicity flipping of the topological in-gap modes emerging in
opposite parameter regions for the two edge geometries. Experimental findings
are interpreted in terms of the mirror winding number defined in the unit cell,
the choice of which exclusively depends on the edge shape. Our work offers a
deeper understanding of the boundary effect on the QSH phase, and pave the way
for studying the spin-dependent topological physics in electric circuits.
