The Oberlaa Caucasian Wingnut

Vienna protects only a handful of Caucasian wingnuts, and this one stands not in a grand park but on a village square at the city's southern edge. The others on the city's list are in better-known places: one in the Stadtpark, two in the Waldmüllerpark, and one 4.10 metres round on Wolkersbergenstraße. This one is on the Bischofplatz in Oberlaa, with a walnut a few metres to one side of it and a robinia to the other in the city's tree inventory. That inventory gives its girth as 2.65 metres. Treat it as the city's figure rather than a clean measurement: wingnuts sucker freely and often grow as several stems, and we have not checked whether this is one trunk or a cluster. The species is the reason to come. A tree of the Caucasus and northern Iran, it carries long leaves built like an oversized ash's and, in summer, hangs its crown with green chains of winged seeds, which is when it is easiest to pick out from across the square. Nobody has dated it, and we have no photograph of it yet. About eighty metres away, on Hintere Liesingbachstraße, stands a protected horse chestnut, so Oberlaa gives you two natural monuments in one short stop. If you go, send us a picture, and tell us how many stems you count.