See It with Flowers: A BioSensor for Radiation
✿ The stamen hairs of the common spiderwort (Tradescantia) are made up of rows of cells in single file, like beads on a string. Fuzzy and blue, they emerge by the hundreds around the stamens that hold up the bright yellow, pollen-filled anthers in the flower center. In 1975, a scientist named Sparrow made a remarkable discovery: the stamen hairs were highly sensitive to nuclear radiation, mutating from blue to pink like the floral equivalent of the canary in the coal mine! The mutation frequency is linear down to very low doses and low exposure rates such that counting the number of pink cells as a percentage of blue ones gives an accurate reading of radiation exposure. Since the cells divide in sequence, the position of the pink cell tells when the radiation exposure occurred. The flowers have been used to monitor radiation leaks around nuclear plants in Japan or as a biosensor for chemical pollutants (http://goo.gl/GTMi9C).
✿ As if this biological oddity were not enough, the flower enjoys a romantic history dating to Captain John Smith, the legendary American settler who was plucked from the perils of death at the hands of the Powhotan tribe by the chief’s daughter Pocohontas. When Smith left Virginia in 1609, he carried with him spiderwort seeds to his friend John Tradescant the Elder, a master gardener in England. The plant was named Tradescantia virginiana in the latter’s honor (http://goo.gl/u9dwVM).
Image Credits: Tradescantia from the garden of Chris Veerabadran whose question about the flower name inspired this post. Thanks, Chris!
Staminal Hair from www.microscopy-uk.org.uk