Excitation spectra of ultracold (T=0.4 K) large aromatic molecules (naphthalene, anthracene, and tetracene) solvated by a few (1-16) He atoms are reported. Measured spectral shifts and vibronic excitations for a series of mass selected He clusters are presented. Clusters on aromatic molecules with an increasing number of rings show unexpected, and size-dependent, spectral effects. We suggest that the novel spectroscopic features are due to the anisotropic delocalization of the He atoms on the surface of the aromatic molecule.