  The most conspicuous property of a semiflexible polymer is its persistence
length, defined as the decay length of tangent correlations along its contour.
Using an efficient stochastic growth algorithm to sample polymers embedded in a
quenched two-dimensional hard-disk fluid, we find apparent wormlike chain
statistics with a renormalized persistence length. We identify a universal form
of the disorder renormalization that suggests itself as a quantitative measure
of molecular crowding.
