Scrophularia vernalis L. (C. and S-Eur., C. and W-As.) – A rare, locally naturalized escape from cultivation. Known at least since 1814 (Durand 1899). By far most records are from Wallonia and in most cases rather ephemeral or only temporarily persisting (van Rompaey & Delvosalle 1978). There seem to be no extant populations in Flanders (Van Landuyt & al. 2006). Doubtlessly best known from Roly (Bois Mouton) where Scrophularia vernalis is naturalized since at least 1861 (confirmed lately). Also naturalized for many decades in Aiseau-Presles (park Oultremont, at least since 1938 but not confirmed lately; see Saintenoy-Simon & Leclercq 1995). In several different other places Scrophularia vernalis persisted for some time but has not been confirmed lately. Herbarium evidence is available, for instance, from Beaumont (ruins of Tour Salamandre, 1882-1888), Gentinnes (1863-1867), Wuustwezel (domain baron Gericke d'Herwijnen, 1949-1956), Modave (La Roche-aux-Corbeaux, 1907-1920), etc. A new population with ca. 50 plants was discovered in Sippenaeken (Plombières) in 2012 (see http://waarnemingen.be). Other recent records (Balen, Bree, Neder-over-Heembeek, etc.) are probably ephemeral. Saintenoy-Simon & Leclercq (1995) provide an interesting and up-to-date overview of Scrophularia vernalis in Belgium.
Scrophularia vernalis is mostly naturalized in woodlands and clearings, usually on calcareous soils. It has also been repeatedly recorded on old walls. Despite its presence in natural habitats it has not been considered an undesirable environmental weed so far.
A very similar species, Scrophularia chrysantha Jaub. et Spach, is also cultivated as an ornamental and has been recorded as an escape (e.g. Chrtek & Skočdopolová 1996, Dvořáková 2000; also known from Scandinavian countries, cf. http://linnaeus.nrm.se/flora/di/scrophularia/scrop/scrochr.html). It is a native from western Asia and might pass as Scrophularia vernalis. It is distinguished by its short, subglobose inflorescences, ca. 2,5 x 3 cm. Especially young plants of Scrophularia vernalis are likely to be confused with it (see also Hartl 1975a, UZUNHİSARCIKLI & al. 2019).
Selected literature:
Chrtek J. & Skočdopolová B. (1996) Scrophularia chrysantha v Cechach. Zprávy Československé botanické společnosti (Prague) 31(1): 79-81.
Durand T. (1899) Phanérogames. In: De Wildeman E. & Durand T., Prodrome de la flore belge. A. Castaigne Editeur, Bruxelles: 1112 p.
Dvořáková M. (2000) Scrophularia. In: Slavík B. (ed.), Květena České republiky, vol. 6. Praha, Academia: 324-332.
Hartl D. (1975a) Scrophularia. In: Hegi G. (ed.), Illustrierte Flora van Mitteleuropa, vol. 6(1) (2nd ed.). Paul Parey Verlag, Berlin & Hamburg: 21-36.
Pépin F. (2016) Scrophularia vernalis L., nouvelle localité en région Centre et bilan national. Bull. Soc. Bot. Centre-Ouest 47: 136-139.
Saintenoy-Simon J. & Leclercq L. (1995) Découverte récente de Scrophularia vernalis L. dans la Région bruxelloise et à Namur. Son statut actuel en Belgique. Adoxa 6-7: 5-9.
UZUNHİSARCIKLI M.E., GÜNER E.D., ÖZBEK F. & EKİCİ M. (2019) Scrophularia vernalis: a new species record for Turkey, and its comparison with S. chrysantha (Scrophulariaceae). Phytotaxa 397(1): 391-398. [available online at: https://www.researchgate.net/publication/331744221_Scrophularia_vernalis...
Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D. (2006) Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 1007 p.
Van Rompaey E. & Delvosalle L. (1978) Atlas de la flore belge et luxembourgeoise. Ptéridophytes et Spermatophytes. Commentaires. Jardin Botanique National de Belgique, Meise: 116 p.