Cistus salviifolius

Family : Cistaceae

Text © Prof. Paolo Grossoni

 

English translation by Mario Beltramini

 

In the nursery practice Cistus salviifolius L. (1753), family Cistaceae Juss. (1789), genus Cistus L. (1753), due to its white flowers with yellow unguis is inserted in the category ‘White or Whitish Pink Clade’. As he wanted to highlight the similarity of its leaves with those of the sage (Salvia officinalis L.) he called it ‘salviifolius’.

It is called cisto femmina, cisto con foglie di salvia, brentina in Italian, Sage-leaved rock-rose in English, ciste à feuilles de sage, ciste femelle in French, Jaguarzo morisco, tomillo, estepa negra, jata negra in Spanish, sargoaço, cergoaçco, saganho-moro in Portuguese, Salbeiblättrige Zistrose in German.

This cistus a shrub (NP) very ramified and, even though it can reach 90-100 cm, has usually a prostrate posture without exceeding about 60 cm; it’s evergreen and is poorly aromatic; the branches are thin, initially viscous, densely tomentose for protective hairs from fasciculate to stellate. The leaves are simple, opposite, rather small (10-40 x 6-320 mm) and briefly petiolate (2-4 mm); the lamina is oval or elliptic and often rounded at the apex, uninerved (penninervis), green-grey on both faces of which the lower is paler; thay have a wrinkled-reticulate appearance and are tomentose; the margin is entire, wavy but not revolute and is ciliated.

With a very long (up to about ten centimetres) peduncle and densely tomentose for stellate hairs, the flower is inserted on a uniflorus inflorescence or, sometimes, with two paired flowers. It is medium sized (4-5 cm of diameter), with little or scent at all and has five petals broadly obovate of candid white colour, but also pale pink, with a yellow unguis at the base.

Blooming occurs between April and May but, even if the petals are very ephemeral, can extend until summer. THe calyx is persistent and is formed by three outer sepals, bigger (10-18 x 7-12 mm) and by two inner and smaller; all fall when the fruit is ripe. The ovary is superior and tomentose and the pollination is entomogamous; the stamens, about one hundred, are long and yellow whilst the style is almost non-existent (at most it is 0,5 mm long).

The fruit ripens in early summer; it’s a loculicidal capsule with five carpels, blackish, globose and with a diameter of 5-7 mm; it has sporadic simple trichomes on the outside and contains many seeds, globose and small (1 mm) that, like in the whole genus, have very prolonged dormancy due to the strength and resistance of the outer teguments that are degraded by the action of the fire or by the synergic one of the atmospheric agents and of the organisms of that environment in order to permit in this way the water and the air to reach the embryonic tissues.

The chromosomal number is the same of the whole genus: 2n = 18.

The plants of Cistus salviifolius can tolerate prolonged drought conditions and, despite being basically acidophilic, they can adapt also to soils derived from limestone substrates. Moreover, they tolerate a certain degree of shading and relatively low temperatures thus being able to live up to altitudes of 1200-1300 m above the sea level reaching also the 1800 m in the warmest sectors of its range.

This cistus is found in bushy plant formations or along the edges of wooded areas, often with heterogeneous plants of various species, from those of the evergreen scrub and of its variants to the cenosis of deciduous thermophilic broadleaf trees, or also at the edge of wooded areas such as pinewoods, cypress woods, holm oak woods, deciduous oakwoods or other typologies of associations.

In the Mediterranean basin they are, usually, formations conditioned by degenerative processes but still referable to the model ‘Mediterranean scrub’ up to cenosis unquestionably degraded like the garrigues.

Its natural distribution concerns most of the Mediterranean basin including the Anatolian coasts of the Black Sea and the Atlantic ones of south-western Europe. Cistus salvifolius is absent only in the Macaronesia archipelagoes and in Crimea. Its range practically corresponds to that of the genus Cistus.

Because of the colour and size of its flowers, Cistus salvifolius is at times mistaken with Cistus clusii, an Dunai, an autochthonous cistus of north-western Africa, of Iberian peninsula and southern Italy (south Sicily and Gargano Promontory). However it can be easily distinguished because the latter has needle-like leaves similar to the rosemary’s ones and calyx formed by only three sepals.

It’s a melliferous plant but, presently, used especially for reducing the erosive processes in exposed terrains, for consolidating the sandy dunes and as windbreak.

In the gardens and in the flower-beds it is employed, combining it to other cisti (Cistus ladanifer L., Cistus albidus L., Cistus monspeliensis L., etc.) or to taxa of other families, to create spots of colour. It is easily propagated by seed or by cutting.

After WFO World Flora Online there are no subspecific recognized entities inside this species. The site reports 52 taxa, once classified in different ranks, from species to form, to which presently is not recognized a taxonomic rank of its own but often still nominated in the nursery sector only.

These 52 taxa are defined by the WFO as synonyms of Cistus salviifolius L. In particular, 10 had been identified as ‘species’ (Cistus), 6 appear as ‘form’, 7 in that ‘prole’ (this taxonomic rank, now out of use, had value in the nursery sector but has been replaced by the present category ‘group-cultivar’), 17 had been defined as ‘variety’, 11 did belong to the no more accepted genus Ledonia Spach and, finally, a last taxon had been classified as ‘variety’ of a species attributed to Ledonia.

Among the more employed varieties we can list ‘Avalanche’, very vigorous, ‘Bonifacio’ and ‘Prostratus’ that, due to their very prostrate posture, tolerate the wind very well. ‘Gold Star’ for the petals with one ample white unguis, ‘Grandifolius’ for the size of its leaves (as the name states), ‘May Snow’ because very floriferous as it is the cultivar ‘Fontfroide’ of the hybrid Cistus × florentinus Lam.

The Sage-leaved rock-rose also hybridizes easily with almost all other species of the genus and not only of the category ‘White or Whitish Pink Clade’ (WWPC).

WFO World Flora Online (2024) listed the following hybrids: Cistus × dubius Pourr. (C. laurifolius × C. salviifolius), Cistus × florentinus Lam. (Cistus monspeliensis × Cistus salviifolius), Cistus × hybridus Pourr. (Cistus populifolius × Cistus salviifolius), Cistus × obtusifolius Sweet (Cistus salviifolius × Cistus inflatus), Cistus × pauranthus Demoly (Cistus parviflorus × Cistus salviifolius) e Cistus × verguinii Coste & Soulié (Cistus ladanifer × Cistus salviifolius).

The list just cited also includes Cistus ‘Gordon Cooper’, a triple hybrid, although with unclear origins, between Cistus salvifolius and the hybrid ‘Ruby Cluster’ which, in turn, was obtained from the hybridisation between Cistus inflatus Pourr. ex J.-P. Demoly and the hybrid Cistus × dansereaui ‘Decumbens’.

 

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