Cistus is a genus of flowering plants in the rockrose family Cistaceae, containing about 20 species (Ellul et al. 2002). They are perennial shrubs found on dry or rocky soils throughout the Mediterranean region, from Morocco and Portugal through to the Middle East, and also on the Canary Islands. The leaves are evergreen, opposite, simple, usually slightly rough-surfaced, 2-8 cm long; in a few species (notably C. ladanifer), the leaves are coated with a highly aromatic resin called labdanum. They have showy 5-petaled flowers ranging from white to purple and dark pink, in a few species with a conspicuous dark red spot at the base of each petal., and together with its many hybrids and cultivars is commonly encountered as a garden flower.
The common name rockrose is applied to the species, a name also shared by the related genera Halimium, Helianthemum and Tuberaria, all in the family Cistaceae.Species
They are thermophilous plants, which require open, sunny places. As with many other Cistaceae, the species of Cistus
have the ability to form mycorrhizal
associations with truffles
) and are thus able to thrive on poor sandy soils or rocks.
Cistus are the only host of Cytinus hypocistis, a small parasitic plant that lives on the roots and is noticeable only for a short period of time when in flower. The presence of the parasite does not seem to hurt the host population.
Cistus species are used as food plants by the larvae of some Lepidoptera species including Coleophora confluella and Coleophora helianthemella, the latter recorded on Cistus monspeliensis.
Several research groups have a special extract of the rockrose (C. incanus ssp. Tauricus) can show that the propagation of the virus flu
) significantly inhibits in vitro without resistance. Possibly, this research to a new treatment for the flu virus, including bird flu
. The effectiveness in humans, however, with scientific studies have not yet been established.