Árbol roble melojo

PYRENEAN OAK

Quercus pirenaica

Carballo negro (Galician) | Carvalho-negral (Portuguese) | Roble melojo (Spanish) | Chêne tauzin (French)


This oak is a large tree that can reach a height of 25 m, despite its heavy exploitation it is often seen re-sprouting and forming tangled groves.

Its principal feature are its leaves that are velvety on both sides and possessing deep lobes. These leaves are simple, alternate and deciduous although in many specimens, especially the younger ones, they remain withered on the tree through the winter and only fall when the new bud pushes them out (marcescent). The flowers grow in long yellowish hanging stalks (catkins) and the acorns are globose and bitter.

Marcescence (or delayed leaf fall) is a phenomenon still not fully understood. The Pyrenean oak is a variant of deciduous plants whose drying leaf separation does not happen until the new leaf bud burst through, the following season. With the autumn and the shortening of the photo period (daylight hours), the plants reabsorb nutrients and water from the leaves, close the conducting vessels and leave the petioles (leaf stalks) mechanically attached to the branches. If the wind does not hinder this, the gentle clamping is sufficient for the tree to keep the leaves dry until the arrival of spring.
However, individual trees in the species don´t exactly behave in the same way, the lower branches retaining more leaves than the higher ones, frequently losing its canopy. In any case, the connection between the marcescence and the intermediate temperament of the Spanish oak, which straddles both the Mediterranean (evergreen) and Atlantic (deciduous) worlds, remains a mystery. It is not clear that retaining the leaves provides any advantages, apart perhaps a greater degree of protection for the new leaf buds.

This oak is well adapted to the Mediterranean climate as seen on the hairs on its leaves, reducing transpiration. It is capable of forming extensive forests, although at times it is associated to other species, always within acidic or lime-free substrates, growing at an altitude ranging from 200 to 2100 m.

Its root system is so strong that new trunks grow directly from the stump. Having been heavily exploited for its wood or for charcoal, we frequently find specimens that, in reality, offshoots from a single individual tree whose stump could be several hundred years old.

The fruit of oaks can at times be confused with excrescence (outgrowths) called galls. These malformations are created by the tree itself as a defence against attack from a type of wasp that deposits an egg in the buds or young shoots. The plant reacts by creating a tumour in such a way that its tissue completely wraps and isolates the parasite, forming a gall. The hatching egg and its larva remain protected and surrounded by food. After the metamorphosis, the insect, now an adult, makes a hole and emerges, leaving the gall to dry up.
The real fruit is the acorn, a distinctive nut from the genus quercus, with an accompanying woody enclosure called a cupule or shell, partially covering it like a beret.

The Pyrenean oak has suffered more than any other representative of the genus, due to the oidium epidemic that devastated them at the start of the 20th century. Its continuous felling promoted the fungus spread, the degeneration and weakening of the species. In some areas, individual trees are found in poor condition or isolated while in other areas, resisting in groups of warped specimens or recovering amongst accompanying species like beech or oak. Unfortunately, many previously populated slopes are now cleared and deforested creating irreversible erosion. For this reason we need to highlight the important role played by the oak in fixing its extended roots in the loosest ground; plying it with nutrients and essentials from the subsoil and depositing them on the surface.

In the province of Alava, the oak extends into the Izki park, while in Bizkaia, extending into Punta Lucero and in Gipuzkoa they can be found in the mountains of Jaizkibel, Igeldo, Andatza and Itziar.

Quercus is the name given by the Romans for oaks in general as well as for their wood, and by extension, all trees that produce acorns. The origin of the word itself is Celtic meaning beautiful tree. The epithet pyrenaica alludes to its original location, but in reality there are few actually there. This is because the German botanist who described the species, Ludwig von Willdenow, had labels with this as its origin and therefore not taking into account its general distribution.

PYRENEAN OAK characteristics

Discover the different parts of the tree are like

Tronco del roble melojo

Trunk

Hoja del roble melojo

Leaf

Flor del roble melojo

Flower

Fruto del roble melojo

Fruit

PYRENEAN OAK flowering

  • JAN
  • FEB
  • MAR
  • APR
  • MAY
  • JUN
  • JUL
  • AUG
  • SEP
  • OCT
  • NOV
  • DEC