Austrian oak

Austrian oak (Quercus cerris)

The austrian oak or turkey oak is an oak native to south-eastern Europe and Asia Minor. It is the type species of Quercus sect. Cerris, a section of the genus characterised by shoot buds surrounded by soft bristles, bristle-tipped leaf lobes, and acorns that usually mature in 18 months.

Quercus cerris is a large deciduous tree growing to 25–40 m tall with a trunk up to 2 m diameter. The bark is dark grey and deeply furrowed. On mature trees the bark fissures are often streaked orange near the base of the trunk. The glossy leaves are 7–14 cm long and 3–5 cm wide, with 6–12 triangular lobes on each side; the regularity of the lobing varies greatly, with some trees having very regular lobes, others much less regular.

The flowers are wind-pollinated catkins, maturing about 18 months after pollination; the fruit is a large acorn, 2.5–4 cm long and 2 cm broad, bicoloured with an orange basal half grading to a green-brown tip; the acorn cup is 2 cm deep, densely covered in soft 4–8 mm long 'mossy' bristles. First year acorns are very bitter, but are eaten by jays and pigeons; squirrels usually only eat them when other food sources have run out.

The tree harbours the gall wasp Andricus quercuscalicis whose larvae seriously damage the acorns of native British oaks. In 1998, the Ministry of Defence ordered the felling of all Turkey oaks on its UK bases.

Branch with fruit (Photo: G. Aas)

Forest with warped oak and fir in Taurus (southern Turkey, photo: G. Aas)