Laurel Forest Habitat

Introduction

The vegetation of the mountain and humid areas of the Canary Islands consists of luxurious groups of evergreen trees with laurel-like leaves which, in Spanish, are called by the characteristic name of "monte verde" or "laurisilva canariense". The trade winds blowing from north-west determine a constant supply of humid air masses which, climbing up the slopes of the mountains, tend to condense creating a dense fog, the thickness of which depends on the season. This fog belt, practically present all the year, is the most important cause of the development on the slopes facing north or north-west, of the optimum microclimate conditions for the expansion of forests dominated by evergreen wooden species of sub-tropical origin. The developing potential area of "monte verde" is included in the strip between 500 and 1,600 meters high, on the north-west slopes in the western islands, and in some conditions (which can be found in the Anaga massif in Tenerife) the lowest limit can go as down as 100 metres above sea level

The trees with laurel-like leaves in the Canary Islands must be regarded as a sort of living Paleo-flora, relict of a kind of sub-tropical humid vegetation which, until the end of the Tertiary period (late Miocene and early Pliocene), could be found in large parts of South Europe and North Africa. In fact, fossils of plants belonging to the genus now still living in the Canary Islands have been discovered in many countries around the Mediterranean: Spain, France, Italy and Georgia. At present, the total extension of the laurel forests does not exceed 6,7% of the total area of the islands. The forests in best repair are located on La Gomera, in several places on Tenerife (Anaga, Los Silos, Guimar, Agua Arcia, San Antonio and lcod); La Palma (Las Sauces); Hierro (Ensenada El Golfo); Gran Canaria (Los Tiles). In the literature this kind of forest is said to be present also on Fuertenventura (Riscos de Jandia) and Lanzarote (Riscos de Famara) but now there is no sign of this kind of vegetation. On every island this kind of forest has different groups of characteristic plants and animals. Among the plants, we can observe the most typical trees and shrubs and the species belonging to the genus Pericallis; among the animals some Coleoptoron (subspecies Carabidae) and the butterflies Columba junionae and Columba Bollei which are only present on La Gomera, La Palma and Tenerife and are now in danger of becoming extinct. It is for this reason that the forests of trees with laurel-like leaves are of primary interest for the European Community. Even if in a few large valleys of Tenerife, La Gomera and La Palma some considerable extension of these woody formations can be found, at present this kind of vegetation is quite degraded as it lies in an area particularly suitable for crops. Among the most interesting and most frequent species we can count: Laurus azorica, Apollonias barbujana, Maytenus canariensis; in the undergrowth we can often observe Viburnum tinus subspecies rigidum, Hedera helix subspecies canariensis and Luzula canariensis. On the borders of these very forests some typical communities of herbs grow. Among them Isoplexis canariensis, Ranunculus cortusifolius, Pericallis cruenta, Pericallis echinata, Vinca major and Sideritis macrostachys.

Some interesting ferns like Adiantum reniforme, Asplenium hemionitis and Davallia canariensis can be observed in the underbrushes where the slopes get steep and in the narrowest and deepest ditches, especially on the rocky parts. Still in the belt where trees with laurel-like leaves live, there are some places where the surrounding conditions - sometimes owing to the action of man - are not so favourable to the growth of these plants. In such areas the "brezales" group of shrubs, dominated by heather, are in the majority: Erica arborea, Erica scoparia subspecies platycodon, often associated with Myrica faya and Hypericum glandulosum. The groups where Erica platycodon is the most frequent plant can be more easily found on the crests of Anaga massif, on the northern part of Tenerife and in the highest part of Inchereda, on La Gomera. It is important to observe that the moors on the islands of Macaronesia represent a priority interest habitat for the European Community. In the sunniest areas where the action of man has given more troubles, we can observe undershrubs belonging to the species of clover. Among them Adenocarpus foliolosus, Cytisus scoparium and sometimes Ulex europaeus species which have probably been introduced only recently.

Seub Franco

It is an endemic plant of the Islands of Macaronesia but it cannot be observed in the islands of Lanzarote and Fuertenventura where it has become extinct probably owing to the action of man. The "laurel of Canary Islands" can be between 10 and 20 meters high, sometimes it may even reach 35 meters. It has an upright trunk with usually smooth grey bark, which can be tomentose in the youngest small branches. It can reach a meter and half in diameter - on La Gomera there is a laurel reaching 1,6 meters in diameter. The evergreen leaves are coriaceous, up to 10-1 5 centimeters long and up to 4-5 centimeters wide and deep green in colour. The axillary yellow-cream flowers are showy and have greenish veins. The fruit is reminiscent of a small blackish olive. Once upon a time it was much used to produce coal.

Appollonias Barbujana

(Lauraceae) Barbusano

It is a tree up to 25-30 meters, with characteristic round-shaped foliage and lined dark grey bark. The ovatelanceolate dark green leaves are shiny, 6-9 centimeters long and up to 4 centimeters wide, practically always with warts. The white flowers are small and very scented. Its berries look like small blackish olives. The "barbusano" is an endemic plant of Canary Islands and Madeira and its presence in these places is particularly interesting because the nearest species is Arnottii living in southern India.

Maytenus Canariensis

(Celastraceae) Perarillo

This small tree not higher than 7-8 meters in rocky places turns into a prostrate shrub. The irregular lined trunk has dark bark, the short and crabbed branches are knotty and the foliage is small and scattered. The persistent shiny green leaves have short petiole, oval blade and toothed margin. The auxiliary small white flowers are grouped in clusters at the highest part of the branches. The fruits are fleshy and divided in three valves. It is an endemic species of Canary Islands

Viburnum Tinus

(Caprifoliaceae) Afollado

It is a typical shrub of the bay-leaf forest underbrush: as it doesn't love light very much, its presence indicates that the stratum of wood is thick with comose young branches shaded. It is a plant up to 5-6 meters high. Its opposite leaves are big (up to 20 centimeters long and 1 2 centimeters wide), very comose, sometimes strigose and reddish. The small white flowers are scented and arranged in rich inflorescences at the end of the branches. It is an endemic plant of the Canary Islands. It can be used as an ornamental plant for gardens and hedges but needs to be kept in the shade.

Hedera Helix Canariensis

(Araliaceae) Hedra

It is a creeping igneous plant which, in the Canary Islands substitutes the common Hedera helix subspecies helix from which it differs by only a few characteristics.

Luzula Canariensis

(Juncaceae)

It is a perennial herbaceous plant with graminaceous leaves characterised by long whitish soft hairs, often arranged at the base and on the margins of the blade. The plant is not higher than half meter and has, on the highest part, a close inflorescence consisting of small white vitreous looking flowers. It is an endemic plant of Canary Islands where it can be observed in the inner part, and sometimes in the borders, of the bay-leaf wood, especially where there are many plants of Erica scoparia subspecies platycodon

Isoplexis Canarienis

(Scrophulariaceae) Crista da Gallo

It is a perennial herbaceous plant with an igneous base of up to one meter high. The lanceolate leaves are coriaceous and scarcely pubescent. The bright red-orange flowers are large - about 3 centimeters long - and are grouped in close inflorescences. Isoplexis canariensis is an endemic plant of the Canary Islands where it can be observed in Tenerife, La Gomera and La Palma. In the island of Gran Canaria two other species, Isoplexis isabelliana Masf. and Isoplexis chalcantha can be found - they differ both for the flowers, which are not bigger than 2 centimeters, and for the closer pubescence.

Ranunculus Cortusifolius

(Ranunculaceae) Morgallana

Among the light and shade at the borders of the bay-leaf woods, some beautiful plants with strongly coloured flowers can be easily recognised. One of them is Ranunculus cortusifolius which is well recognisable for the large yellow flowers. It is an herbaceous plant up to 60 centimetres high and densely comose. The orbicular leaves are up to 30 centimeters wide. The flowers are up to 5 centimeters in diameter.

Pericallis Echinata

(Compositae)

It is a perennial herbaceous plant up to 30-50 centimeters high, with orbicular, round shaped leaves varying from hairless to slightly pubescent, kept by a small petiole with some leaf processes. The flower heads are pinkish and reach two and a half centimeters in diameter. It can be found on the island of Tenerife.

Pericallis Cruenta

(Compositae)

This plant is very similar to the previous one from which it can be easily recognised for the leaves which have a carmine-pink lower face owing to the thick tomentum covering it. Like Pericallis echinata, this species can only be observed in Tenerife.

Vinca Major

(Asclepiadaceae)

This plant has been introduced by man but thanks to the extremely favourable climate it has easily become naturalised. It is a creeping plant with evergreen opposite leaves. The purple-blue or violet flowers are not very big and they are characterised by a calyx canal up to 15 centimeters long with an open part of five centimeters - the result is quite ornamental. Many are the cultivars.

Sideritis Macrostachys

(Labiatae)

In the Canary Islands the genus Sideritis is represented by many species, some of which are known for a few very isolated groups which are difficult to locate. Sideritis macrostachys itself is a very rare species which can be observed on the humid rocks in the strip of bay-leaf trees in the Anaga area in Tenerife. It is a small shrub, not higher than one meter, with very large ovate leaves white-felt owing to the thick tomentum in the lower face and grey-greenish in the upper part. The whitish flowers have a hint of brown but they are very showy for their calyx which is covered by the same white tomentum as the leaves; they are grouped in a close inflorescence, spike-like and sometimes branched at the base.

Adiantum Reniforme

(Adiantaceae)

As in the case of Asplenium, this is a genus of fern with cosmopolitan range of which A. capillus-veneris is surely the most common representative. Adiantum reniforme is a small fern with reniform leaves not wider than 4-5 centimetres which are carried by a petiole up to 20 centimetres long. This small fern lives in shadowy, hot and humid habitats and therefore finds its ideal place on the rocks in bay-leaf woods. This plant can only be observed in the islands of Macaronesia.

Asplenium Hemionitis

(Aspleniaceae)

This fern lives in the western Mediterranean countries and in the islands of Macaronesia - it in fact needs very humid and quite hot habitats. The leaves are usually narrow and long with a base widened into a sort of big ears arrangement, at the centre of which sits the petiole.

Davallia Canariensis

(Davalliaceae)

On the dry-stone walls and on the rocks inside the strip of bay-leaf wood we can observe this characteristic fern easily recognisable for the long creeping rhizome which is completely covered with reddish hairs. The green leaves are up to 45 centimeters long and up to 30 centimeters wide. As the two other ferns, also "Davallia of the Canary Islands" has a range going from the western part of the Mediterranean to the Macaronesia.

Erica Arborfa

(Ercaceae) Brejo

It is a species with a vast range covering south Europe, the Mediterranean countries, the central and eastern African mountains and the Macaronesian islands. Its presence is bound to substrata poor in calcium, like the ones with volcanic origin. It is a small tree which can reach 7-8 meters in height, especially in well-preserved woods. The dark green leaves are needle-shaped, quite rigid and small (not longer than 6-8 millimeters). The tiny white-pink flowers are grouped in clusters at the apex of the highest branches, therefore, when the plant is in bloom it is really beautiful and it is often used as an ornamental species. Erica arborea is typical of the groups of high shrubs called "fayalbrezal", in which it is associated with other species. In extremely degraded conditions, such as the ones following fires, it may become invasive and constitute almost mono-species groups of undershrubs.

Erica Scoparia

(Ercaceae) Tejo

In the Canary Islands there are two species of erica: Erica arborea (brejo) and the Frica scoparia subspecies platycodon (tejo). Even if the general appearance of the two plants often living together is almost the same, there are some characteristics which can easily be observed helping the identification: "Erica arborea" has young branches covered with white tomentum with leaves not longer than 8 millimetres and white-pinkish flowers; "Erica scoparia" has hairless branches with a bark exfoliating in longitudinal direction, leaves up to 15 millimeters long with revolute margins making the leaves look fleshy with pink-reddish flowers. Erica scoparia subspecies platycodon is an endemic plant of Macronesia

Hypericum Glandulosum

(Hypericaceae) Hiperico

It is a shrub up to one meter high with thin and slender resinous trunks, often visible on the borders of the bay-leaf woods. The opposite leaves are ovate-elliptic with glandular hairs on the margins. The gold-yellow flowers are arranged at the apex of the branches. The sepals have the same glandular hairs as the leaves. Hypericum glandulosum is an endemic plant of the islands of the Macaronesia.

Adenocarpus Foliolosus

(Leguminosae) Codeso

It is a shrub very similar to Adenocarpus viscosus and can be recognised by the absence of glandular hairs, especially in the calyx, making it less viscous. It lives at lower height, usually beneath 1200-1400 metres, while Adenocarpus viscosus lives at higher altitudes.

Cytisus Scoparius

(Leguminosae)

It is an upright shrub with small branches with quadrangular section; the leaves are small and trifoliate. The yellow flowers are large (25 millimeters) and carried on the highest branches in close inflorescences. The legume is black and covered with dense hair. It is a species with European range and it has recently been introduced by man into the Canary Islands. The "broom" is also a species with ornamental value both for its flowers and for its leaves, which in the different cultivars have several colour hues.

Ulex Europaeus

(Leguminosae)

Even if Ulex europaeus is not a wild species of the Canary Islands, but the result of a recent introduction by man, the surroundings are so ideal that it grows very well and it is able to enter the coenosis with the "broom". It can easily be recognised as it is covered with thorns.