Phalaris arundinacea
Environmental Weed (2024)
Common names
reed canary grass
Biostatus
Exotic
Category
Vascular
Structural class
Grasses
Simplified description
Tall grass, up to 2 m tall with leaf-blades up to 40 cm long and 2 cm wide arranged on often upright stems, producing a large flowerhead up to 30 cm long and 4 cm across, either an open branched head or closed to a spike.
Flower colours
Green, Purple
Detailed description
Robust perennials, 60–200 cm, with long-creeping rhizomes. Leaf-sheath chartaceous, glabrous, striate, light brown. Ligule 2.5–7.5–(10) mm, entire, but soon lacerate. Leaf-blade 20–40 cm × 8–20 mm, ribs numerous, fine, adaxially smooth but scabrid near tip, abaxially with strong midrib near base, ribs densely, minutely scabrid; margins minutely scabrid, long-narrowed to scabrid, acute tip. Culm 50–180 cm. Panicle 9–30 × 1.5–4 cm, lanceolate or oblong, lobed below; rachis smooth below, scabrid above, branches scabrid, spreading at anthesis. Spikelets 4–5.5 mm, pale green or purplish. Glumes ± equal, 3-nerved, lanceolate, keeled but not winged, acute to acuminate, minutely scabrid, rarely lower glume with minute hairs near margin. Ø florets: lemmas equal, 1.3–1.6 mm, narrow, short-hairy. ⚥ florets: lemma 3–4 mm, broadly keeled, lanceolate, acute, firm and shining below, short-hairy above; palea much narrower than lemma; anthers (2)–2.5–3.2 mm; caryopsis c. 2 × 1 mm.
Similar taxa
Much more robust than other wetland grasses with the exception of the rare pest plants Manchurian wild rice and phragmites.
Distribution
Scattered throughout New Zealand.
Habitat
Swamps. Including under shade of willows and open kahikatea forest, wet grassland, margins of water bodies, wet waste areas and roadsides.
Conservation status
Not applicable
Detailed taxonomy
Family
Ecology
Flowering
October–January
Fruiting
Autumn
Year naturalised
1874
Origin
Europe, Asia, North America and South Africa
Reason for introduction
Pasture plant, also ornamental plant.
Control techniques
Can be controlled manually, mechanically or herbicidally depending on situation.
Life cycle and dispersal
Seed dispersed by water, animals or contaminated machinery.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
PHAARU
Referencing and citations
References and further reading
Edgar E, Connor HE. 2000. Flora of New Zealand. Vol. V. Grasses. Manaaki Whenua Press, Christchurch, NZ. 650 p.
Attribution
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Edgar and Connor (2000).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.