Plants of South Eastern New South Wales
Myriophyllum aquaticum
Common name
Parrots feather
Family
Haloragaceae
Where found
In and around waterways and freshwater dams and lakes. Mainly Sydney area. Occasionally elsewhere.
Notes
Introduced perennial aquatic or semi-aquatic herb, rooting at the lower nodes, forming dense mats of vegetation on the water surface. Stems glaucous, to 5 m long, usually emerging up to 0.30 m above the water. Leaves whorled, glaucous. Emergent leaves crowded at the tips of the stems, glaucous, usually in whorls of 5-6, mostly 2.5-3.5 cm long, 5-15 mm wide, deeply dissected into 20-36 linear segments, appearing feathery. Submerged leaves in whorls of 4-6, to 4 cm long, 8-12 mm wide, dissected. Male and female flowers on different plants. Only female plants in Australia. Female flowers white, tiny, 0.5 mm in diameter, with 4 sepals, 0 petals, single at the base of whorled leaves. Flowers mostly spring–summer.
General Biosecurity Duty all NSW. Pest plant ACT.
Definite identification of species of Myriophyllum often requires microscopic examination of the seed cases, beyond the scope of this key.
PlantNETdescription: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Myriophyllum~aquaticum (accessed 24 January, 2021)
This identification key and fact sheets are available as a free mobile application:
