Chamaenerion Ség.
Chamaenerion is a genus of eight species, native to the temperate regions of the northern hemisphere (mainly Eurasia). One species, Chamaenerion angustifolium (L.) Scop. (syn.: Epilobium angustifolium L., Chamerion angustifolium (L.) Holub), is a common and increasing native species (Lambinon & Verloove 2012). At least three additional species are cultivated as ornamentals in Europe: Chamaenerion dodonaei (Vill.) Schur (syn.: Epilobium dodonaei Vill., Chamerion dodonaei (Vill.) Holub), C. fleischeri (Hochst.) Fritsch (syn.: Epilobium fleischeri Hochst., Chamerion fleischeri (Hochst.) Holub) and C. latifolium (L.) Sweet (syn.: Epilobium latifolium L., Chamerion latifolium (L.) Holub) (Hoch 1997, Jäger & al. 2008).
Molecular analysis strongly supports segregation of Chamaenerion from Epilobium (Baum & al. 1994) and this taxonomy is now widely followed (see also Wagner & al. 2007, Stace 2010).
When treated separately from Epilobium, the group of species with zygomorphic flowers and alternate leaves has the correct generic name Chamaenerion Ség. while Chamerion (Raf.) Raf. ex Holub is a later heterotypic synonym (Sennikov 2011).
1 Leaves linear-lanceolate, up to 5 mm wide with obscure central vein. Seeds papillose, 1,5-2 mm. Petal without claw === Chamaenerion dodonaei
Leaves lanceolate, usually much wider (at least in well-developed plants) with distinct central and submarginal veins. Seeds smooth, 1-1.3 mm. Petal with short claw (native) === C. angustifolium
Literature:
Baum D.A., Sytsma K.J. & Hoch P.C. (1994) The phylogeny of Epilobium (Onagraceae) based on nuclear ribosomal DNA sequences. Syst. Bot. 19: 363-388.
Hoch P.C. (1997) Chamerion. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 5. Cambridge University Press, Cambridge: 357-358.
Holub J. (1972) Taxonomic and nomenclatural remarks on Chamaenerion auct. Folia Geobot. Phytotax. 7: 81-90.
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Lambinon J. & Verloove F. (avec coll. Delvosalle L., Toussaint B., Geerinck D., Hoste I., Van Rossum F., Cornier B., Schumacker R., Vanderpoorten A. & Vannerom H.) (2012) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Sixième édition. Jardin botanique national de Belgique, Meise: CXXXIX + 1195 p.
Raven P.H. (1976) Generic and sectional delimitation in Onagraceae, tribe Epilobieae. Ann. Missouri Bot. Gard. 63: 326-340.
Sennikov A.N. (2011) Chamerion or Chamaenerion (Onagraceae)? The old story in new words. Taxon 60: 1485-1488.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Wagner W.L., Hoch P.C. & Raven P.H. (2007) Revised classification of the Onagraceae. Syst. Bot. Monogr. 83: 1-240.