Scirpus atrovirens Willd. subsp. georgianus (R.M. Harper) Verloove et Lambinon (Verloove & Lambinon 2011) [syn.: S. georgianus R.M. Harper, S. atrovirens Willd. var. georgianus (R.M. Harper) Fernald] (N-Am.) – A very rare, locally naturalized alien. Known since 2003 from a military base in Marche-en-Famenne where Scirpus atrovirens subsp. georgianus was possibly introduced by military troops (although an unintentional introduction by migrating birds is also feasable). Its populations were initially restricted to a small training area for tank manoeuvres but it is fast spreading in the past years. According to Saintenoy-Simon (2008), Saintenoy-Simon & al. (2009) and Saintenoy-Simon & Giot (2010) Scirpus atrovirens behaves like an invasive alien and might out-compete native, vulnerable species. In Marche-en-Famenne it grows in wet depressions, ditches,… and accompanies rare native species like Juncus tenageia L. f. Since 2006 it is also known from Nivelles (abandoned racing circuit) where it is found in damp meadows. Its vector of introduction remains unclear.
Scirpus atrovirens subsp. georgianus is part of a taxonomically difficult species-complex (S. atrovirens s.l.). Recent taxonomists tend to treat the taxon here concerned at specific rank (Whittemore & Schuyler 2002). Elsewhere in western and central Europe Scirpus atrovirens s.l. has been recorded on various occasions, especially in France and Germany (see references). The exact identity of these populations is somewhat unclear: those from the Jura in France have been ascribed to var. pallidus Britton (syn.: S. pallidus (Britton) Fernald) (Litzler 2000) but most probably belong to subsp. georgianus (see for instance Schnittler & Niedbala 1993, Zelnik 2004) or, even more likely, subsp. hattorianus (Verloove 2014).
Selected literature
Gerstberger P. (1994) Die Neophyten Glyceria striata und Scirpus atrovirens im Rheinischen Schiefergebirge bei Oberwinter. Decheniana 147: 44-48.
Giot J.-L. (2004) Notes et réflexions militaro-botaniques concernant Scirpus atrovirens trouvé sur le camp militaire de Marche. Les Barbouillons 216: 1-3.
Korneck D. & Schnittler M. (1994) Glyceria striata und Scirpus atrovirens im Rheinland. Flor. Rundbr. 28: 29-36.
Lannoy M. (2004) Présence de Scirpus atrovirens Willd. à Marche-en-Famenne. Les Barbouillons 216: 4-6.
Litzler P. (2000) Nouveaux loisirs botaniques de retraite. Monde Pl. 468: 12.
Maslo S. & Šarić Š. (2017) Georgia Bulrush, Scirpus georgianus (Cyperaceae): a new alien species in the flora of Bosnia and Herzegovina and the Balkans. Phytologia Balcanica 23(3): 405–407. [available online at: http://www.bio.bas.bg/~phytolbalcan/PDF/23_3/PhytolBalcan_23-3_11_Maslo_...
Nobis A., Nobis M. & Klichowska E. (2014) Scirpus georgianus. In: Nobis M. & al. (eds.), Contribution to the flora of Asian and European countries: new national and regional vascular plant records, 2. Acta Bot. Gallica 161(2): 218-219.
Prost J.-F. (2000) Scirpus atrovirens Willd. dans le Jura. Monde Pl. 470: 15.
Saintenoy-Simon J. (ed.) (2008) Trouvailles floristiques récentes (2006-2007. Adoxa 59: 17-51.
Saintenoy-Simon J., Champluvier D. & Giot J.-L. (2009) Le camp militaire Roi Albert (Marche-en-Famenne): récapitulation de son intérêt floristique. Adoxa 61: 29-39.
Saintenoy-Simon J. & Giot J.-L. (2010) Excursion dans le camp militaire Roi Albert de Marche-en-Famenne, le 25 juillet 2009. Adoxa 65-66: 21-26.
Schnittler M. & Niedbala J. (1993) Zur Unterscheidung von Scirpus atrovirens Willd., Scirpus sylvaticus und ähnlichen Cyperaceen. Flor. Rundbr. 27(1): 25-31.
Verloove F. (2014) Scirpus hattorianus (Cyperaceae), newly reported for Europe, naturalized in France. Willdenowia 44: 51-55. [available online at: http://alienplantsbelgium.be/sites/alienplantsbelgium.be/files/wi44-1e_2014_p51-55_verloove_1394784850203.pdf]
Verloove F. & Lambinon J. (2011) The non-native vascular flora of Belgium: new combinations and a new variety. New Journ. Bot. 1(1): 38-42.
Zelnik I. (2004) Scirpus georgianus Harper – a new species in Slovenian flora and character species of the association Dactylorhizo majalis-Scirpetum georgiani ass. nova. Hacquetia 3(2): 94-105.