CISTACEAE (Rockrose Family)

Plants perennial herbs (small shrubs elsewhere), sometimes woody at the base. Stems creeping to erect. Leaves alternate or less commonly opposite or whorled, relatively small, sessile or short-petiolate. Stipules absent. Leaf blades simple, the margins entire, sometimes somewhat curled under, with pinnate veins or sometimes only a midvein. Inflorescences terminal or appearing axillary, of solitary flowers or more commonly ranging from small clusters to racemes or panicles, the branches sometimes appearing racemose and with the flowers mainly along the upper side. Flowers actinomorphic, perfect, hypogynous, often subtended by bracts (these usually shed as the fruit matures). Cleistogamous flowers sometimes present (in Helianthemum). Calyces of 5 sepals, these free or fused at the base, in 2 whorls, the outer 2 narrower, shorter than, and sometimes partially fused to the inner 3, all persistent at fruiting. Corollas of 3 or 5 free petals. Stamens 3 to numerous, the anthers attached at their bases, dehiscent by longitudinal slits. Pistil 1 per flower, of 3 fused carpels. Ovary superior, with 1 locule (incompletely 3-locular, the locule thus appearing lobed in cross-section), the placentation parietal. Style absent or 1 per flower and short, the stigmas 1 or 3. Fruits capsules, 3-valved, dehiscent longitudinally. Eight genera, about 200 species, nearly worldwide.

Some members of the rockrose genus Cistus are cultivated as garden ornamentals, but these generally are not winter-hardy as far north as Missouri. A few species are grown or wild-harvested commercially for the bitter, gummy resins extracted from their twigs and used as scent agents in soaps and deodorants.