Cistus өсімдігі: Сипаттамасы мен ерекшеліктері

Genus of flowering plants in the rock rose family Cistaceae

Cistus (from the Greek kistos) 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. Cistus, with its many hybrids and cultivars, is commonly encountered as a garden flower. The common name rockrose (rock rose in the UK) is applied to the species, a name also shared by the related genera Halimium, Helianthemum and Tuberaria, all in the family Cistaceae. The common name gum cistus is applied to resin bearing species, especially C. ladanifer.

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.

They are thermophilous plants, which require open, sunny places. This plant genus is peculiar in that it has developed a range of specific adaptations to resist summer drought and frequent disturbance events, such as fire and grazing. In addition, it can form both ectomycorrhizas and arbuscular mycorrhizas. More than 200 ectomycorrhiza forming fungal species belonging to 40 genera have been reported so far to be associated with Cistus. Cistus plants are therefore considered pyrophytes, or plants which rely upon fire as a part of their life cycle to encourage spread within their biome. Cistus seeds are resistant to the fires allowing them to germinate once fires have subsided and allowing them to benefit from an environment with less competition from other species.