Rubia L.
Genus composed of about 80 species in temperate and Mediterranean areas, widely distributed across Europe, Africa, Asia and America. Includes perennial herbs, or unusually small shrubs, often with woody base and climbing lianas. They have characteristic quadrangular stems with hooked retrorse trichomes and verticillate coriaceous leaves, in groups of 4-6, with scabrid margins. In North Africa there are 3 species, ± lianoid, of which only 1 is clearly woody, R. tenuifolia.
The following species are lianoid, herbaceous perennial plants, sometimes with woody base, rhizomes and stolons, that are found in North Africa in the Mediterranean areas near the coast: R. peregrina L. and R. tinctorum L. The latter, often naturalised from ancient cultivation that were established for its traditional use as dye plant. In the Canary Islands, there is an endemic species, a woody chamaephyte: Rubia fruticosa Aiton.
Updated by: H. Sainz & J. Charco.