Zizania is a small genus of four aquatic species, three in North America and one in Asia. They are commonly known as “Water oats” or “Wild rice”. Some are cultivated as ornamentals or for their edible roots. Species of Zizania are recently sometimes introduced as water-garden ornamentals in ponds in Belgium (and elsewhere in Europe). The usual garden plant seems to be the Asian perennial Zizania latifolia (Clement 2000, Hollings & Hollings 2000, Page 2000). A second species, the North American Zizania aquatica L., was reported as introduced in some lakes in Belgium (Woluwé, Barse-Marchin,…) (see Saintenoy-Simon & Duvigneaud 1998). These records require confirmation. It is an annual and perhaps less likely to be cultivated as an ornamental (see however Jäger & al. 2008, also Marshall 2003). For convenience both are included in the key beneath that only relies on vegetative characters (flowering plants have not been recorded so far in the wild in Belgium).
Clement E.J. (2000) More about Zizania latifolia. BSBI News 83: 40-41.
Hollings M. & Hollings O. (2000) Zizania latifolia – fit and flourishing over-abundantly in a West Sussex pond. BSBI News 85: 39-40.
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.
Marshall P. (2003) Zizania aquatica in Britain. BSBI News 93: 56.
Page K.W. (2000) Zizania latifolia (Poaceae) naturalized in Surrey (v.c. 17). BSBI News 84: 38-39 (+ frontcover).
Saintenoy-Simon J. & Duvigneaud J. (1998) Les plantes aquatiques ou palustres introduites. Adoxa 20-21: 35-40.
Terrell E.E. (2007) Zizania. In: Barkworth M.E. & al. (eds.), Flora of North America north of Mexico, vol. 24: 47-51. Oxford University Press, New York-Oxford.
Terrell E.E., Peterson P.M., Reveal J.L. & Duvall M.R. (1997) Taxonomy of North American species of Zizania (Poaceae). Sida 17: 533-549.