Zizania latifolia (Poaceae) in the EPPO region: addition to the EPPO Alert List
Why
Zizania latifolia (Poaceae) is a perennial rhizomatous species found in damp habitats. In the EPPO region, it shows invasive behaviour in Lithuania, Russia, and Ukraine. The EPPO Panel on Invasive Alien Plants are seeking further information on the occurrence and behaviour of Z. latifolia in the EPPO region.
Geographical distribution
EPPO region: Belarus, Belgium, Kazakhstan, Lithuania, Russia (Central Russia, European Russia, Russian Far East*), Ukraine, United Kingdom.
Asia (native): China (Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Shaanxi, Shandong, Sichuan, Yunnan, Zhejiang), Japan, Mongolia, Myanmar, Taiwan.
North America: USA (Hawaii).
Oceania: New Zealand.
* Zizania latifolia is native to the Russian Far East.
Morphology
Culms erect, 1–2.5 m (taller in the non-native range), ca. 1 cm thick, rooting at lower nodes, nodes glabrous. Leaf sheaths longer than internodes, thickened, lower sheaths tessellate; leaf blades broadly linear, 50–90 × 1.5–3.5 cm, abaxial surface scabrous, adaxial surface glabrous, tapering to base, apex abruptly narrowed to a long point. Panicle 30–50 × 10–15 cm.
Biology and Ecology
In the EPPO region, Z. latifolia rarely flowers and seed-set has not been reported. Zizania latifolia can grow vigorously and forms dense monospecific stands. In Lithuania, extensive cover has been recorded (2 500 m2).
Habitats
Zizania latifolia is an aquatic plant species which can tolerate fresh, brackish and saline water. It can be found at the margins of ponds and canals, wetlands and tidal flats. It is also found along ditches or any slow flowing water body.
Pathways for movement
Zizania latifolia is thought to have been introduced into New Zealand via soil ballast from ships. It has been introduced into several countries as a food crop (cultivated throughout Asia), a fodder crop and as an ornamental pond plant. In the introduced range, spread is mainly human mediated. Drainage machinery, boats and trailers can all act to spread rhizome fragments. Z. latifolia can spread locally via rhizome fragmentation that can be moved through the water course.
Impacts
Zizania latifolia can invade and degrade pastureland which can cause low lying pastures to become waterlogged. It can also clog drainage systems increasing the risk of flooding. Z. latifolia can form dense monocultures which can outcompete native biodiversity causing impacts on ecosystem services.
Control
Zizania latifolia is a difficult species to control due to the habitats it invades. Additionally, rhizomes fragments should be removed to avoid re-growth. Herbicides are the most effective control measure, but their use is restricted because many chemicals can affect the biota in waterways.
Sources
Dubovik DV, Sauchuk SS, Zavialove LV (2021) The current status of the plant invasions in Belarus. Environmental and Socio-economic studies 9, 14-22.
Leostrin A, Pergl J (2021) Alien flora in a boreal region of European Russia: an example of Kostroma oblast. Biological Invasions 23, 3337–3350. https://doi.org/10.1007/s10530-021-02589-2
Liatukas Z, Stukonis V (2009) Zizania latifolia – a new alien plant in Lithuania. Botanica Lithuanica 15, 17-24.