Oak, holm (Quercus ilex)
Holm oak is an evergreen broadleaf tree native to the Mediterranean region.
Common name: holm oak
Scientific name: Quercus ilex
UK provenance: non-native
Interesting fact: holm oak is also known as 'holly oak', and its botanical name, Quercus ilex, refers to its similarity to holly, which is in the Ilex genus.
What does holm oak look like?
Habit: holm oak can grow to 20m and develop a huge, rounded crown. It was introduced to Britain in the late 1500s. The bark is black and finely cracked, and twigs are slender and covered with light brown felt-like hairs.
Leaves: oval, dark green to black and concave with a similar coating of pale hairs on the underside. Young leaves and leaves on young plants are spiny, like holly leaves, whereas older leaves and leaves on old plants have smooth edges.
Flowers: catkins, and yellow male catkins can be seen to hang off the tree in abundance in early spring.
Fruits: after pollination by wind, female flowers develop into acorns, which are smaller and have a more pointed tip than those of English or sessile oaks. Young acorns are green and mature to a dark red-brown before falling.
Look out for: the leaves are glossy above and downy below without lobes. Young leaves can be toothed.
Could be confused with: unlikely to be confused with anything. Holm oak differs from most oaks as its leaves are spiny, like holly.
Identified in winter by: it is an evergreen so its features are present year round.
Where to find holm oak
Holm oak is a native to the Eastern Mediterranean but has been naturalised in the UK. It is one of the few evergreen oak trees found in Britain today and lends itself well to shaping - the shrub/bushy part of the tree is reasonably fast growing (the stem stays the same height). It is found growing in a variety of situations, such as parks and gardens.
Trees are resistant to salt-spray from the sea, and are often planted as a windbreak in coastal situations. However, during severe winters they are prone to dying or losing their leaves, so are more commonly found in the south of the UK.
Value to wildlife
Holm oak is not as valuable to wildlife as native English and sessile oaks, but its catkins provide a source of pollen for bees and other insects, while its dense, evergreen canopy offers year-round shelter for birds.
Mythology and symbolism
In ancient Greece the leaves of the holm oak were used to tell the future and they were also used to make crowns to honour people. The acorn was seen as a sign of fertility and wearing acorn jewellery was believed to increase fertility. In Greek lore, the primitive tribes of Arkadia were said to have lived on a stable diet of acorns.
How we use holm oak
Holm oak timber is incredibly hard and strong. The Romans used the wood for making the wheels of carts and carriages, as well as agricultural tools. Today it is sometimes used for firewood as it is slow and long lasting. Holm oak acorns are used to feed pigs reared for Iberico ham.
Holm oak is less susceptible to pests and pathogens than our native English and sessile oaks, although it may be susceptible to Acute oak decline (AOD) and chronic oak decline (COD).