Sylvanshine
Sylvanshine is an
optical phenomenon in which dew-covered trees of
species whose leaves are wax-covered
retroreflects beams of light, as from a vehicle's headlights, sometimes causing trees to appear to be snow-covered at night during the summer. The phenomenon was named and explained in 1994 by Professor Alistair Fraser of
Pennsylvania State University, an expert in
meteorological optics. According to his explanation, the wax on the leaves causes water to form beads, which become, in effect,
lenses.
Reference
Alistair B. Fraser. The Sylvanshine: retroreflection in dew-covered trees. Applied Optics., 33, 21, 4539-4547. 1994