Quercus ilex
Holm oak
Holm oak, holly oak, evergreen oak (Eng), encina, carrasca, chaparro (Spa), alzina (Cat), artea (Baq), aciñeira (Glg), azinheira (Por).
Native
DID YOU KNOW...? The holm oak is the most representative tree on the Iberian Peninsula.
This tree has a variable form, a dense crown and a thick, dark trunk. Its leaves are persistent, alternate, dark green on the upper side and covered by a dense, whitish tomentum on the underside making them velvety-looking. The yellow-ochre flowers bloom in the spring grouped onto hanging twigs (catkins), and the fruits (acorns) may be sweet or bitter. Flora Iberica differentiates two general types:
Quercus ilex L. subsp. ballota (Desf.) Samp. (= Quercus rotundifolia Lam.). Up to 15 m tall with a rounded crown. The leaves are normally elliptical or rounded. They are up to 6 cm long and often have a spiky margin.
Quercus ilex L. subsp.
ilex. Up to 25 m tall with a more elongated and less dense
crown. The leaves are generally
lanceolate or
elliptical, and up to 9 cm long. The
margin is usually
toothed or
entire and is rarely spiky.
ECOLOGY
The holm oak is the most characteristic species of Mediterranean forests. It is indifferent to soil type and grows from sea level up to 1300-1400 m, exceptionally reaching altitudes of 2000 m. The subspecies ballota usually forms pure woodlands, and lives where there is a wide temperature range (continental climate), being able to better withstand frosts and prolonged droughts. The subspecies ilex occurs in zones where the climate is more temperate, humid, and coastal, not penetrating very far into the interior, and also prefers lime-rich soils. Although it also forms pure masses, these holm oak woodlands are richer because there are more accompanying species.
DISTRIBUTION
This species lives across the entire Mediterranean region; nevertheless, the subspecies ballota ranges throughout the Iberian Peninsula, mainly in the interior, whereas the subspecies ilex is distributed across the zones nearest the Cantabrian and Mediterranean coasts (Balearics and from Catalonia to Almería). In the areas where they overlap, they hibridise, and the distinguishing characteristics are diluted.
