May 2018: Common (English, German) oak [Quercus robur] (Stiel-Eiche, Sommer-Eiche): After a very warm April the oak's buds opened in mid-April already and the tree was almost in full leaf at the end of April - what a wonderful shining light green the young oak leaves show! The leaves are lobed to about half the leaf blade and are not exactly symmetric in contrast to the sessile oak [Quercus petraea, syn.: Quercus sessilis, Quercus sessiliflora]: its leaves are less lobed and almost symmetric. Later in the year they often show galls. Oak galls were used to produce gall ink in former times. The wood is very durable and dense. Oaks can get very old: up to 1000 years or more (Germany's oldest oak is said to be 1400 years old!). Therefore they are often used for dendrochronology and thus help date wood.
