Applying the "exact WKB method" (cf. Delabaere-Dillinger-Pham) to the stati
onary one-dimensional Schrodinger equation with polynomial potential, one i
s led to a multivalued complex action-integral function. This function is a
(hyper)elliptic integral; the sheet structure of its Riemann surface above
the plane of its values has interesting properties : the projection of its
branch-points is in general a dense subset of the plane, and there is a gr
oup of symmetries acting on the surface. The distribution of the branch poi
nts on the surface is of crucial importance, because it gives the position
for the obstacles to Borel-Laplace summation of the WKB-symbols. In "Approc
he de la resurgence" by B. Candelpergher, J.-C. Nosmas et F. Pham, p. 103-1
05, an attempt has been made towards giving an explicit construction of the
surface with paper, scissors and glue; here we give the correct constructi
on and in addition we prove that each surface constructed in this way comes
from a polynomial potential. Along the way we are lead to an elementary co
njecture in the theory of holomorphic functions.