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.
Alistair B. Fraser. The Sylvanshine: retroreflection in dew-covered trees. Applied Optics., 33, 21, 4539-4547. 1994