Bornholmer Strasse runs through our neighborhood as it heads west to the famous Bösebrücke (the first border crossing that opened when the Berlin Wall fell in 1989). Like other street names in the area, it is distinctively Scandinavian. The Danish island of Bornholm – among other places around the Baltic sea – is home to the Swedish Whitebeam (Sorbus intermedia), a medium-sized tree that is frequently featured in landscape architechture. Swedish Whitebeam and the two other Sorbus species mentioned below line both sides of Paul-Robeson-Strasse just west of Arminplatz (see our Berlin Plants map). The bright red Sorbus berries announce their presence in mid-summer and last well into November. When harvested at the correct time and properly cooked, all Sorbus fruits on Paul-Robeson-Strasse are edible, although their sometimes bitter or mealy taste is best tempered in jams.
Rowan (Sorbus aucuparia), sometimes called Mountain Ash, has a distinguished history as a tree with magical and medicinal properties, in addition to having fruits that were traditionally used in jellies to accompany game meats. They are best harvested after the first frost (see bletting) and used for making spirits or jams. The mashed and sieved fruit can be used to flavor bread dough and the dried fruit can provide a sour snack or flavoring for tea. The fresh fruit eaten in large quantities can upset the stomach, although it is hard to imagine anyone enjoying the bitterness of the fresh fruit for more than a few berries! Rowan fruit contains vitamin C and is the source of sorbic acid, a preservative you may have noticed on food labels.
Common Whitebeam (Sorbus aria) is known as “Mehlbeere” (flour berry) in Germany, a name best understood when eating the dry, mealy berries of the tree. Like Rowan, whitebeam fruits are generally harvested after the first frost and their preparation and use is very similar to Rowan fruits, although their taste is quite different. Tea made from the fresh berries has been used as a general stomach regulator: used for both loose bowels and constipation. The bitter seeds contain low levels of cyanogenic glycosides similar to what is found in apples, cherries and other fruit seeds, hence they are best avoided.
The Sorbus genus comprises a large variety of species; for more information and interesting trivia, take a look at this blog which is devoted entirely to Sorbus trees!