The Dogwood Bunchberry, "Cornus canadensis", has a flower which opens its petals and fires pollen in less than 0.5 milliseconds. The record is currently held by the White Mulberry tree, "Morus alba", whose leaves are used to cultivate silkworms. It is also notable for the rapid release of its pollen, which is launched at over half the speed of sound. The stamens act as catapults, releasing stored elastic energy in just 25 µs. "This is the fastest motion yet observed in biology, and approaches the theoretical physical limits for movements in plants".