Rhamnus L.
Taxonomically controversial genus, composed of about 110 species, distributed mainly across temperate and subtropical regions of the Northern Hemisphere, with some representatives further S in Africa and South America. In North Africa it is represented by 7 species, distributed through the Mediterranean area. They are woody plants of varying sizes, from creeping subshrubs (Rh. pumila, Rh. myrtifolia, Rh. serpyllacea) to species that sometimes reach tree habit (Rh. cathartica, Rh. alpina, Rh. alaternus).
Henning, T. & Raab-Straube, E. von 2016: Rhamnaceae in Euro+Med Plantbase – the information resource for Euro-Mediterranean plant diversity [Fecha consulta: 19/5/2017].
Ruiz de la Torre, J. 2006. Flora Mayor. Ministerio de Medio Ambiente. Organismo Autónomo Parques Nacionales. Dirección General para la Biodiversidad. Madrid.
Key to species
1 Deciduous shrubs 2
1 Evergreen shrubs 5
2 Shrubs slightly spiny. Leaves opposite, at least lower leaves Rhamnus cathartica
2 Shrubs spiny. Leaves alternate 3
3 Creeping subshrub up to 0.5 m. Flowers yellow Rhamnus pumila
3 Erect shrub 1-4 m. Flowers greenish or reddish-yellow 4
4 Leaf margin irregularly crenate-dentate. Flowers greenish Rhamnus alpina
4 Leaf margin entire. Flowers yellow-red Rhamnus disperma
5 Shrubs with spiny branches. Flowers tetramerous Rhamnus lycioides
5 Shrubs or subshrubs with non-spiny branches 6
6 Shrub or small tree up to 8 m. Flowers pentamerous Rhamnus alaternus
6 Subshrubs usually creeping which rarely exceed 0.5 m. Flowers pentamerous or tetramerous 7
7 Leaves coriaceous, hard, semirigid, dentate, bright green. Flowers pentamerous Rhamnus myrtifolia
7 Leaves slightly or not coriaceous, soft, entire or with some teeth on the upper half, greyish-green. Flowers tetramerous Rhamnus serpyllacea
Updated by: M. Cueto, E. Giménez & J. Charco.