T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Zizania latifolia (Manchurian wild rice)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Subfamily: Ehrhartoideae
Tribe: Oryzeae
Genus: Zizania
Species: Z. latifolia
Binomial name: Zizania latifolia
Synonyms: Hydropyrum latifolium, Zizania caduciflora
Common names: Manchurian rice grass, 

Zizania latifolia is a large semi-aquatic grass from China that has run rampant on riverbanks, ditches in parts of the North Island from Northland to the Kapiti Coast. It is abundant on the margins of Northern Wairoa River in Northland.

It is tall rhizomatous, perennial, grass that grows up to 3 m tall. It has long, straight, light to dull green leaves that grow in fans. The leaves are 2- 3 cm wide and up to 2.5 m long and have a stout midrib and taper to a point.During November, December it develops a reddish brown flower head that is 40- 60 cm long. Established plants spread by long, stout rhizomes and form dense impenetrable swards. The seeds are spread by water or by drainage machinery.

Zizania latifolia is real problem plant because it replaces all other species. It also causes silt to accumulate causing flooding which destroys aquatic flora and fauna habitats. 
Any suspected new sightings should be reported immediately by contacting MAF Biosecurity New Zealand on 0800 80 99 66

NIWA’s interesting web page on Manchurian wild rice:  https://www.niwa.co.nz/aquatic-biodiversity-and-biosecurity/update/issue-05-2003/stopping-the-freshwater-wild-rice-invader