Cork oak

• Scientific name: Quercus suber
• Family: Fagaceae (beech, oak, sweet chestnut)
• Also known as: Sorbriero

Evergreen tree up to 26m tall. Bark deeply fissured and corky, up to 15cm thick in places. Leaves weakly lobed with a slight point at the tip, up to 4cm long. Each tree has male and female flowers (monoecious). Acorns solitary or paired and are deeply cupped by the upper scales. Pollinated by wind.

Facts 

• Cork is a kind of bark where the dead cells are waterproofed by a wax called suberin. Most trees produce some cork but the cork oak produces lots!
• One cubic centimetre of cork contains 40 million air cells. It is warm to the touch, durable, light, bouncy, chemically inert, and the suction-cup effect of the cut cells makes it stick to a bottle neck.

South-western Europe (France, Corsica, Italy, Sardinia, Sicily, Portugal, Spain) and northern Africa (Algeria, Morocco, Tunisia). The cork oak favours acidic soils, requires a hot dry summer season and a cold and moist winter, and can be found in open woodlands, on hills and lower slopes at 300–1000m altitude.

Common uses

• Cork is one of the world's most important renewable forest products. The cork bark is stripped off the tree in a thick cylindrical layer. Each tree is harvested every nine years.
• A single tree can cork 4,000 bottles. Fine wines can develop through the happy marriage between cork and a bottle made tall enough to lie on its side. The wine ‘breathes’ through the cork as it ages.
• Cork is a biodegradeable alternative to environmentally unfriendly PVC flooring. It is hard-wearing, very sound absorbent and agreeable to walk on due to reflection of warmth and its natural bounce. Cork is also used in insulation, floats, engine gaskets and even skirts, heels and handbags!

• Portuguese Cork Association

Glossary

• Lobe: incomplete division in any plant organ (eg leaf).
• Scale: overlapping structure on cone or fruit.