Cistaceae is a natural order of polypetalous exogens, consisting of low shrubby plants or herbs with entire leaves and crumpled, generally ephemeral, showy flowers. Some exude a balsamic resin, such as ladanum from a Levant species of Cistus. Four species of the genusHelianthemum are found in Britain, and are popularly known as the 'rock-rose.' Research Cistaceae