Crocosmia Planch.
Crocosmia is a genus of ca. 9 species, all native to South Africa and Madagascar (Mabberley 2008). Most species have conspicuous orange-red flowers and are fairly popular garden plants (Cullen 1986). Artificial hybridization considerably blurred specific boundaries. Plants in cultivation are nowadays mostly complex hybrids. In Belgium and neighboring territories probably only Crocosmia xcrocosmiiflora is genuinely hardy (Jäger & al. 2008). Stace (2010), however, reports four taxa from throughout the British Isles. Crocosmia being hardly represented in Belgian herbaria, the exact identity of the plants currently found in the wild requires further study. However, most plants seen have perianth lobes that equal the tube in length, a feature only encountered (among the plants found in cultivation) in C. xcrocosmiiflora and C. masoniorum (L. Bolus) N.E. Br. (Jäger & al. 2008, Stace 2010). The latter is distinguished by its wider leaves (at least some 30 mm wide or more) and corollas (perianth at least 45 mm) and may have been overlooked. Some records may be referable to another hybrid, Crocosmia xcurtonus nom. illeg. (?) 'Lucifer' (see: http://waarnemingen.be/soort/view/799721). Such hybrids seem to be at least as hardy as C. xcrocosmiiflora and are probably widely cultivated. They are easily told apart based on their pleated leaves. The issue requires further study.
Although genetically distinct (Goldblatt & al. 2008), Chasmanthe R. Br. is a very similar genus, and both genera have been confused. It shares the Iris-like leaves and zygomorphic orange-red flowers with Crocosmia. However, Chasmanthe is readily distinguished by upper perianth segments that are at least twice as long as the others (while all are more or less equal in Crocosmia).
Literature:
Cullen J. (1986) Crocosmia. In: Walters S.M. & al. (eds.), The European Garden Flora, vol. 1: 386. Cambridge University Press, Cambridge.
De Vos M.P. (1984) The African genus Crocosmia Planchon. Journ. South Afr. Bot. 50: 463-502.
De Vos M.P. & Goldblatt P. (1999) Crocosmia. In : Flora of Southern Africa, vol. 7. Iridaceae, part 2, Ixioideae. Fascicle 1: Ixieae (first part): Ixiinae and Tritoniinae (Ixia, Dierama, Tritonia, Crocosmia, Duthiastrum, Chasmanthe, Devia and Sparaxis). Pretoria: National Botanical Institute: 129-138.
Goldblatt P., Manning J.C. & Dunlop G. (2004) Crocosmia and Chasmanthe: biology, classification and cultivation. Portland: Timber Press.
Goldblatt P., Rodriguez A., Powell M.P., Jonathan Davies T., Manning J.C., van der Bank M. & Savolainen V. (2008) Iridaceae ‘Out of Australasia’? Phylogeny, Biogeography, and Divergence Time Based on Plastid DNA Sequences. Systematic Botany 33(3): 495-508. [available online at: http://biology.mcgill.ca/faculty/davies/pdfs/Goldblatt%20et%20al.%202008.pdf]
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.
Kostelijk P. (1984) Crocosmia in gardens. The Plantsman 5: 246-253.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Stewart O.M. (1988) Tritonia Ker-Gawler (Crocosmia Planchon). Plant Crib 1988: 117.
Veldkamp J.F. (1997) Overlooked genera and species in the Malesian flora: the case of Crocosmia (Iridaceae) and some others. Flora Males. Bull. 11(8): 511-514.