Sorbus pseudothuringiaca
The Hersbrucker Whitebeam (Sorbus pseudothuringiaca ) is a plant of the genus flour berries ( Sorbus ) in the rose family ( Rosaceae ). Within the haws it belongs to the Sorbus hybrida group, thus forming a hybrid between the Real Whitebeam (Sorbus aria- group) and rowan (Sorbus aucuparia ).
Features
The Hersbrucker Whitebeam is a medium sized tree or shrub. The leaves measure 8-10 × 5-8 cm and are in autumn elliptical. They strongly resemble the leaves of Sorbus × pinnatifida var thuringiaca. They have 4-5 lobes, which are about 1.5 inches long, inclined and moderately serrated and rarely cut to the midrib. The leaf stalks are 15 to 20 millimeters long, slightly hairy and rather coarse. The upper leaf surface shining, the lower leaf surface is hairy and woolly hardly glabrous. The hairs have a diameter of 6 to 8 ( rarely to 12) microns. There are 9-10 pairs of lateral veins present. The inflorescence has a diameter of 4.5 to 5 centimeters and consists of 40 to 45 petals. The flowers have a diameter of 11-13 millimeters. The fruits are red, round, apple-shaped and have a diameter of about 9 to 11 millimeters. They contain very few, small lenticels, which have a diameter of less than 0.1 millimeters. The seeds are blackish.
Occurrence
The Hersbrucker Whitebeam is endemic in Bavaria, in the Franconian Jura. It occurs mainly between Hersbruck and Pegnitz, also at Gössweinstein at the Wiesentfels and possibly also at Ebermannstadt and Forchheim. It is the southernmost occurrence were until now stocks at Reicheltshofen and Unterriedenberg SE Deinschwang occupied. In their habitat requirements, the type is more like the rowan. Thus, their growth places are on the tops of the Hersbrucker Alb markedly increased within the 900 -mm rainfall line. Below 600 meters above sea level. NN. are hardly found occurrence. The species grows in light, rather mesophilic -humid forest communities in more or less absonnigen documents. Heaped stocks occur on the skeleton shaped, flattish tops of the highest elevations of the Franconian Alb, where dolomite forms the base. In the middle Frankenjura it grows on and near the plateau edge of the Jurassic especially on dolomite.
Endangering
The Hersbrucker Whitebeam applies nationwide, according to the Red List of endangered plant species as safely. According to the Red List of Bavaria, the species is classified at level 3 as endangered. Germany has a very large responsibility for the conservation of the species. Within Germany, the state of Bavaria comes to the sole responsibility for the Artentwicklung the Bavarian endemics.
Botanical history
Towards the end of the 19th century this type was interpreted as a bastard and in the local flora of August Friedrich Schwarz as Sorbus hybrida Koch ( = pirus aucuparia aria = Pirus hybrida Smith = Sorbus hybrida Koch) listed several sites.
In 1961, the Hersbrucker Whitebeam by Ruprecht Duell was first described. He gave the clan as erbfestes taxon species rank. Konrad Gauckler, expanding the known to date sites and noted the growth places on the newly found manuscript maps created from black. Otto Warburg & Zoltan Karpati preconceived 1968 the species as intermediate type of Sorbus aucuparia Sorbus austriaci and on. Duell (1961) and Kützelnigg (1995 ) took a position in front of the Sorbus hybrida group. This was due to observed similarities of style with Sorbus x pinnatifida nm thuringiaca.