Smyrnium perfoliatum L. (Medit.) – A rare but increasing, locally naturalized escape from cultivation. Recorded in 1850 near Tournai and in 1942 in Leuven (Fabri 1993). In the past years increasingly observed and locally persisting well. Known in Aartselaar since 2009 (confirmed in 2014: 5 flowering plants). Also repeatedly seen in Herentals (2009-2011), Tiegem (since 2012), Steenbrugge (since 2013), Essen (since 2013: 28 flowering plants) and Willebroek (nature reserve Arkenbos, since 2013). Probably the largest population (with many dozens of individuals) was discovered in 2016 in Mortsel. An up-to-date overview with Belgian observations is available here: http://waarnemingen.be/soort/view/9174. Despite being a southern species, it is increasingly seen in northern Europe, even in Scandinavia (e.g. Fröberg 2010).
Smyrnium perfoliatum is usually seen in grassy places, often in half shade (roadsides, by tracks, etc.). It is a biennial species.
The similar Smyrnium olusatrum L. was formerly more frequently grown and now is naturalized in parts of western Europe, including the British Isles and the Netherlands (van der Meijden 2005, Stace 2010). It was claimed from Belgium as well (e.g. Durand 1899) but not a single herbarium collection confirms this. Its upper stem leaves are divided and not clasping stem and its foliage is dark green, not yellowish green like in S. perfoliatum.
Selected literature:
Durand T. (1899) Phanérogames. In: De Wildeman E. & Durand T., Prodrome de la flore belge. A. Castaigne Editeur, Bruxelles: 1112 p.
Fabri R. (1993) Umbelliferae. In: Flore Générale de Belgique, vol. 5, fasc. 2. Jardin Botanique de l’Etat, Bruxelles: 105-360.
Fröberg L. (2010) Smyrnium. In: Jonsell B. & Karlsson T. (eds.), Flora Nordica, vol. 6. The Swedish Museum of Natural History, Stockholm: 273.
Jäger E.J. (1998) Beiträge zur Wuchsform und Biologie der Gefäßpflanzen des herzynischen Raumes. 2: Smyrnium perfoliatum L. (Apiaceae). Hercynia N.F. 31: 103-116. [available online at: http://public.bibliothek.uni-halle.de/index.php/hercynia/article/view/509]
Müller J. (1988) Smyrnium perfoliatum L. na Moravě. Zpr. Čs. Bot. Společ. 23: 101-104.
Peniastekova M., Pisut I., Letz R. & Ferakova V. (1996) Notes on the distribution, ecology and origin of the species Smyrnium perfoliatum L. in Slovakia (in Slovak). Bull. Slov. Bot. Spol. Bratislava 18: 92-97.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Valenta V. (1998) Je smyrnium prerastenolisté (Smyrnium perfoliatum L.) na južných výbežkoch Malých Karpát ohrozeným druhom? (Is Smyrnium perfoliatum L. an endangered species on the southern spurs of the Malé Karpaty Mts?). Bull. Slov. Bot. Spoločn. 20: 125-129.
Van der Meijden R. (2005) Heukels’ Flora van Nederland (23e druk). Wolters-Noordhoff, Groningen: 685 p.