Rhamnus lycioides
Encyclopedia
Rhamnus lycioides, black hawthorn, european buckthorn, mediterranean buckthorn, is a species of flowering plant shrub in the Rhamnaceae
Rhamnaceae
Rhamnaceae, the Buckthorn family, is a large family of flowering plants, mostly trees, shrubs and some vines.The family contains 50-60 genera and approximately 870-900 species. The Rhamnaceae have a worldwide distribution, but are more common in the subtropical and tropical regions...

 (buckthorn) family, in the Rhamnus genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

. It is found in the Mediterranean region, in southern Europe
Southern Europe
The term Southern Europe, at its most general definition, is used to mean "all countries in the south of Europe". However, the concept, at different times, has had different meanings, providing additional political, linguistic and cultural context to the definition in addition to the typical...

 and northern Africa.

Description

Rhamnus lycioides is a slow growth shrub adapted to dry Mediterranean climate
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...

. It is deciduous or evergreen, shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 of 1.5-3 meters high with a tangled, thorny and many branched form. The bark is grayish stems and these are topped with spikes. Older branches are gray.

Leaves are light green and, 0.5 to 3.5 centimeters long and 0.3 to 1 inch wide. The tip is obtuse to apiculate. It has narrow leaves entire, flat, linear-spatulate to obtuse. The leaf is entire is linear to obovate, glabrous, narrow and elongated sometimes slightly broadened towards the apex. They are sometimes leathery and persistent. Lateral nerves have little or no markings on the underside.

The yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

 s are inconspicuous, standing in groups and appear in the winter. The calyx shows four sharp corners.
Flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

 is very small, solitary or in small bundles in the axils of the leaves, greenish-yellow with 4 triangular lobes. The petal
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...

s are rudimentary or nonexistent. The yellow flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

 s are inconspicuous, standing in groups and appearing in the winter. The calyx shows four sharp corners.

The fruits ovoid, 4-6 millimeters large, yellowish and are beginning to ripen black. The fruit is a globose berry, with little meat, which resembles a tiny green grape initially and black at maturity. The berry is having inside a single seed or more, depending on the subspecies. Fruit round, small, dark.

It does not bloom and bear fruit at the same time. Several specimens of the same population bear fruit in different months extending the availability of the species as food for birds, such as the warbler
Warbler
There are a number of Passeriformes called "warblers". They are not particularly closely related, but share some characteristics, such as being fairly small, vocal and insectivorous....

s, that disperse their seeds. The berry is purgative and in large quantities is toxic to humans.

Ecology

In the Iberian Peninsula is distributed throughout the central, eastern and south and its natural habitat are the sclerophyllous forest, and woods of pines, oaks, holm oaks and quercus coccifera. Its scientific name, and sometimes even its common name refers to its resemblance to the botanical genus lycium.

The species is found in the Mediterranean region, particularly in Spain and the Balearic Islands
Balearic Islands
The Balearic Islands are an archipelago of Spain in the western Mediterranean Sea, near the eastern coast of the Iberian Peninsula.The four largest islands are: Majorca, Minorca, Ibiza and Formentera. The archipelago forms an autonomous community and a province of Spain with Palma as the capital...

. It also grows on the Apennine Peninsula and in former Yugoslavia
Yugoslavia
Yugoslavia refers to three political entities that existed successively on the western part of the Balkans during most of the 20th century....

 on rocky, nutrient-poor soils.

The plant appears in sclerophyllous forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...

s, scrub, and even solitary in severely degraded drylands as a pioneer species as the species is resilient to overgrazing and trampling by livestock. It is very resistant to drought, preferring calcareous soils. In extremely dry and windy climates it appears in the rocks. It survives in desert areas with annual rainfall of 200 mm.

The plant thrives in dry forests and bushes, under the Kermes oak
Kermes Oak
Quercus coccifera, the Kermes Oak, is an oak in the Turkey oak section Quercus sect. Cerris. It is native to the western Mediterranean region and Northern African Maghreb, from Morocco and Portugal east to Libya and Greece.-Description:...

, the Holm oak
Holm Oak
Quercus ilex, the Holm Oak or Holly Oak is a large evergreen oak native to the Mediterranean region. It takes its name from holm, an ancient name for holly...

, Aleppo pine
Aleppo Pine
Pinus halepensis, commonly known as the Aleppo Pine, is a pine native to the Mediterranean region. Their range extends from Morocco and Spain north to southern France, Italy and Croatia, and east to Greece and northern Tunisia, and Libya, with an outlying population in Syria, Lebanon, southern...

 and juniper. It is a very hardy plant, which occupies poor soils, gritty and highly eroded. Along with the gorse and thistles are the latest species to disappear in overgrazed areas, being of inestimable value to small birds for its fruit and as the protection and support for their nests. The species is very important for desert birds by their fruits with high water content. The fruit can cause death in mammals, but is consumed by ants and birds.

Classification

Carl von Linné have described the Rhamnus lycioides subspecies Oleoides as a separate species Rhamnus oleoides, but it was in 1932 attributed to Rhamnus lycioides.

Subspecies

Four subspecies of the black thorn have been identified:
  • Rhamnus lycioides ssp. borgiae (Borja) - on the Mediterranean coast east of the Iberian Peninsula
    Iberian Peninsula
    The Iberian Peninsula , sometimes called Iberia, is located in the extreme southwest of Europe and includes the modern-day sovereign states of Spain, Portugal and Andorra, as well as the British Overseas Territory of Gibraltar...

    .
  • Rhamnus lycioides ssp. oleoides (Olive tree) - on the Atlantic and west of the peninsula,.
  • Rhamnus lycioides ssp. velutina (velvet) - in the provinces of Murcia, Almería, Granada and Malaga.
  • Rhamnus lycioides ssp. lycioides - widespread.
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