Iris germanica L. s.l. (hort.) – A rather frequent escape from cultivation or garden throw-out but often only temporarily established in road verges, railway banks, on dumps (see for instance Lebeau 1954) or in waste land. Locally naturalized, however, for instance in coastal dunes (e.g. near Oostduinkerke and doubtlessly elsewhere). Known at least since the 19th century from rocky slopes in Wallonia (especially valley of river Meuse, for instance near Dinant and Huy), confirmed lately (although many populations have disappeared with the former vineyards; see Lebeau 1965).
Iris germanica is treated in a broad sense here and includes I. germanica s.str. and several other complex hybrids of garden origin, involving I. germanica s.str., I. pallida Lam. and I. variegata L. Adolphi (1995) provides an extensive account of the Iris germanica-group in western Germany. He cites Iris flavescens DC., I. sambucina L. and I. squalens L. According to Henderson (1992, 1993) from the end of the 19th century onwards several eastern Mediterranean taxa were involved in the breeding of Iris germanica. The plants resulting from hybridization with those other species should, according to him, be called Iris xconglomerata Henderson.
Selected literature:
Adolphi K. (1995) Neophytische Kultur- und Anbaupflanzen als Kulturflüchtlinge des Rheinlandes. Nardus 2: 1-272.
Bugnon F. & Mbaya N. (1976) La feuille "unifaciale" des Monocotyledones et son interpretation: cas de l'Iris germanica L. Compt. R. Hebd. Seances Acad. Sci., D (Paris) 283(1): 33-36.
Colasante M. & Ricci I. (1977) Iris germanica L. e Iris marsica Ricci e Colasante: separazione delle due specie. Ann. Bot. (Italy) 34: 17-26.
Henderson N.C. (1992) What is Iris germanica? Bull. Amer. Iris Soc. 286: 6-11.
Henderson N.C. (1993) Iris x conglomerata. Bull. Amer. Iris Soc. 290: 17-22.
Koul V. (1976) A tetramerous mutant of Iris germanica. Geobios (Jodhpur) 3(1): 36.
Lebeau J. (1954) Plantes trouvées en 1952 et 1953 au terrain d’immondices de la Ville de Charleroi à Jamioulx, au cours d’une cinquantaine de promenades. Nat. Mosana 6: 59-61.
Lebeau J. (1965) Excursion-circuit du 29 août 1965 dans la province de Liège. Nat. Mosana 18(4): 129-132.
Service N. (1999) Observations of the distribution of Iris germanica L. in south-western Europe. Iris Year Book 1999: 87-94.
Service N. (2002) On the distribution of Iris germanica L. Ann. Bot. n.s. (Italy) 1(2): 177.