Silene conoidea L. (Medit., SW-As.) – A rare and much decreasing, ephemeral alien. First collected in sandy fields near Liège in 1876. Subsequently seen in several different, widely scattered localities. Exceptionally seen as a wool alien in the Vesdre valley in 1890 and 1891. More often seen near grain mills, for instance in Wilsele in 1893 and 1894. Much decreasing in the 20th century and apparently always associated with cereals. Seen on municipal dumps in Mechelen (1948) and Heppen (1964) and on a grain dump in Bilstain and Andrimont in 1954 and 1955. Last recorded in the port of Roeselare in 1994 (near a grain mill; Verloove & Vandenberghe 1995) and on an unloading quay for cereals in the port of Antwerpen in 2011. In Germany also seen as an impurity in Trifolium resupinatum seed (Dickoré & al. 2009).
Silene conoidea is rather poorly distinguished from native S. conica. Extreme forms are readily distinguished but both seem to be linked by intermediates. Such intermediate plants can be ascribed to Silene conica subsp. subconica (Friv.) Gavioli, a native of Greece and Turkey (see Kurtto 2001) and are possibly overlooked in Belgium. Plants observed as an urban pavement weed in the city of Gent in 2007 probably belong here. Silene conica subsp. conica, subsp. subconica and S. conoidea are distinguished as follows (cf. Kurtto 2001):
Silene conica subsp. conica: calyx 10-15 mm long, carpophore 1-2 mm long, capsule 7-12 mm long
Silene conica subsp. subconica: calyx 13-18 mm long, carpophore 2-4 mm long, capsule ca. 8 mm long
Silene conoidea: calyx 18-28 mm long, carpophore ca. 2 mm long, capsule 15-16 mm long
Yet another, very similar species, Silene coniflora Nees ex DC. (a native from SW Asia) was formerly recorded in North America (Morton 2005) and should also be looked for. It is much reminiscent of Silene conica but has shorter petals that hardly exceed the calyx.
Selected literature:
Dickoré W.B., Lewejohann K. & Urner R. (2012) Neufunde, Bestätigungen und Verluste in der Flora von Göttingen (Süd-Niedersachsen). Florist. Rundbriefe 42: 5-59.
Dubrule Reed M. (2004) Silene conoidea (Caryophyllaceae) new to Texas. Sida Contrib. Bot. 21(1): 493-494.
Gerstberger P. (1977) Silene conoidea L. in der Begleitflora von Trifolium resupinatum L. im Rheinland. Göttinger Florist. Rundbr. 10: 91-94.
Khoshoo T.N. (1963) Cyytogenetical approach to the taxonomy of Silene conoidea-conica complex. Proc. Indian Acad. Sci. B., 57B: 368-378.
Kurtto A. (2001) Caryophyllaceae. In: Jonsell B. (ed.), Flora Nordica, vol. 2. The Bergius Foundation, Stockholm: 83-216.
Verloove F. & Vandenberghe C. (1995) Nieuwe en interessante voederadventieven voor de Belgische en Noordfranse flora, hoofdzakelijk in 1994. Dumortiera 61-62: 23-45.
Walter E. (1979) Pflanzen, von denen in der mitteleuropäischen Literatur selten oder gar keine Abbildungen zu finden sind: 11. Silene conoidea L., ein weiterer Gast in Nordbayern. Göttinger Flor. Rundbr. 13(1): 20-21.