Cistus | |
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Cistus monspeliensis | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Malvales |
Family: | Cistaceae |
Genus: | Cistus L. (1753) |
Species [1] | |
34; see text | |
Synonyms [1] | |
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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 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.
Cistus and Halimium form a cohesive and the most derived clade within Cistaceae. [2] Plants of the World Online and World Flora Online treat Halimium as a synonym of Cistus. [3] [4] Molecular phylogenetic analyses conducted between 2005 and 2011 confirm that Cistus species divide into two well-defined clades, neither of which was fully resolved internally. The first clade consists of those with purple and pink flowers (the "purple pink clade" or PPC). The second clade consists of those with white flowers or, in the case of Cistus parviflorus, pale pink flowers (the "white or whitish pink clade" or WWPC). [2] [5] [6] [7] Although the flower colour of C. parviflorus is anomalous, it has very short styles, otherwise characteristic of WWPC species. A hybrid origin has been suggested. [5] A simplified cladogram is shown below: [8]
Species-level cladogram of Cistus species. | ||||||||||||||
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Species-level cladogram of Cistus species, based on plastid and nuclear DNA sequences. [5] [2] [6] [7] |
Within the purple pink clade (PPC), C. crispus is consistently the first diverging species. C. albidus, C. creticus and C. heterophyllus form a well supported clade. Seven species endemic to the Canary Islands form a polytomy, resolved differently in different analyses, in which subtaxa of some species do not always cluster together. Within the white and whitish pink clade (WWPC), there is weak support for a clade consisting of C. clusii and C. munbyi; the other species either formed part of a polytomy or resolved differently in different analyses. Halimium and Cistus were regularly shown to be paraphyletic with respect to one another. [7]
The following species are recognised in the genus Cistus: [1] [7]
In addition a large number of hybrids have been recorded, including: [1] [9]
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. [19] As with many other Cistaceae, the species of Cistus have the ability to form mycorrhizal associations with truffles (Tuber) and are thus able to thrive on poor sandy soils or rocks. Cistus ladanifer has been found to have mycorrhizal associations with Boletus edulis , Boletus rhodoxanthus , and Laccaria laccata . [20]
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 harm 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.
Various Cistus species are known to emit volatile oils, rendering the plants flammable. Their emission of these essential oils is a genetic adaptation for the species intended to actually promote flammability and even cause spontaneous combustion. [21] 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. [22]
Cistuses are suitable for sunny gardens with a nearly frost-free Mediterranean climate. The hardiest of the species is C. laurifolius, which survived the hard frost at Royal Botanical Gardens at Kew in 1895 that eliminated all the cistuses save this and two white-flowered natural hybrids, C. × corbariensis, already grown by John Tradescant the Elder, and C. × loretii, a 19th-century introduction. [23]
Cultivars (those marked agm have gained the Royal Horticultural Society's Award of Garden Merit) include:
The Cistaceae are a small family of plants known for their beautiful shrubs, which are profusely covered by flowers at the time of blossom. This family consists of about 170(-200) species in eight genera that are not very distinct, distributed primarily in the temperate areas of Europe and the Mediterranean basin, but also found in North America; a limited number of species are found in South America. Most Cistaceae are subshrubs and low shrubs, and some are herbaceous. They prefer dry and sunny habitats. Cistaceae grow well on poor soils, and many of them are cultivated in gardens.
Cistus creticus is a species of shrubby plant in the family Cistaceae. Though it usually has pink flowers, of 4.5–5 cm diameter, this species is very variable. It is widely known as a decorative plant. It is frequently called "Cistus incanus".
Cistus salviifolius, common names sage-leaved rock-rose, salvia cistus or Gallipoli rose, is a shrub of the family Cistaceae.
Cistus monspeliensis is a species of rockrose known by the common name Montpellier cistus or narrow-leaved cistus. It is native to southern Europe and northern Africa, in the Mediterranean forests, woodlands, and scrub ecosystems of matorral—maquis shrublands.
Parafomoria cistivora is a moth of the family Nepticulidae. It is found in the western Mediterranean region.
Cistus laurifolius, commonly called laurel-leaf cistus, laurel-leaved cistus or laurel-leaved rock rose, is a species of highly branched flowering evergreen shrub native to some areas around the Mediterranean.
Cistus ocymoides, the basil-leaved rock rose, is a species of flowering plant in the family Cistaceae, native to Portugal and Spain in the Iberian Peninsula, and northern Morocco in Northwest Africa. It is an erect evergreen shrub growing to 60 cm (24 in) tall by 100 cm (3 ft) wide, with woolly grey-green leaves and bright yellow flowers in spring. The flowers may have a dark brown blotch at the base of each petal.
Cistus albidus, the grey-leaved cistus, is a shrubby species of flowering plant in the family Cistaceae, with pink to purple flowers, native to south-western Europe and western north Africa.
Cistus asper is a shrubby species of flowering plant in the family Cistaceae with purple-pink flowers. It was first described in 2005 and is endemic to El Hierro in the Canary Islands.
Cistus chinamadensis is a shrubby species of flowering plant in the family Cistaceae, with purple-pink flowers, first described in 1991. It is endemic to the Canary Islands, where three subspecies occur on three separate islands. The species has been assessed as endangered in the IUCN Red List, being known only from small separated areas and facing a variety of threats.
Cistus clusii is a shrubby species of flowering plant in the family Cistaceae, with white flowers, native to south west and south central Europe and north Africa. It has been wrongly called Cistus libanotis by many authors.
Cistus crispus is a shrubby species of flowering plant in the family Cistaceae, with pink to purple flowers, native to south-western Europe and western north Africa.
Cistus heterophyllus is a shrubby species of flowering plant in the family Cistaceae.
Cistus horrens is a shrubby species of flowering plant in the family Cistaceae, with purple to pink flowers. It is endemic to Gran Canaria in the Canary Islands. First described as a species in 2004, it was previously identified as Cistus symphytifolius, which it resembles.
Cistus inflatus is a shrubby species of flowering plant in the family Cistaceae, often known as Cistus psilosepalus, although this name is a synonym of the hybrid Cistus × laxus. It has white flowers.
Cistus munbyi is a shrubby species of flowering plant in the family Cistaceae, with white flowers. Related to and resembling Cistus clusii, it is native to Morocco and Algeria in western north Africa.
Cistus palmensis is a shrubby species of flowering plant in the family Cistaceae.
Cistus parviflorus is a shrubby species of flowering plant in the family Cistaceae.
Cistus symphytifolius is a shrubby species of flowering plant in the family Cistaceae. It is endemic to the Canary Islands".
Cistus × skanbergii is a compact, bushy variety of rockrose, with pale pink flowers and grey-green foliage. It is also known by the common name dwarf pink rockrose.