At dusk, a lily can turn scent into a signal flare, releasing its richest odor when the air cools and its intended visitors begin to fly. The timing is deliberate. As light falls, many bees withdraw, while hawkmoths and other nocturnal moths use olfaction to locate nectar over distance. This is courtship by chemistry.This is no decorative perfume. In moth-pollinated lilies, circadian regulation ca...More