Plants of South Eastern New South Wales
Myriophyllum verrucosum
Common name
Red water-milfoil, Water-milfoil
Family
Haloragaceae
Where found
Mud and water to 4 m deep. ACT and tablelands. Ranges north of the Hume Highway. Occasional elsewhere.
Notes
Perennial herb, hairless, rooting at the lower nodes. Stems to 1.5 m long, to 0.03 m tall when growing in mud. Emergent leaves usually in whorls of 3-4, rarely 5, 0.3-0.9 cm long, to 3 mm wide, glaucous green to reddish purple, the lower leaves deeply dissected, upper leaves entire. Submerged leaves in whorls of 3-4, 0.4-1.2 cm long, dissected into 8-20 fine segments like the teeth of a comb. Male and female flowers on the same plant, occasional flowers bisexual. Male flowers with 4 yellow hooded petals, each 1.5-2.5 mm long, which fall off easily. Female flowers with 4 minute sepals and 0 petals, and white stigmas. Flowers single at the base of whorled leaves. Flowers throughout the year.
Plants growing on mud are stunted and produce flowers, while those growing in deep, fast-flowing water do not flower.
Definite identification of species of Myriophyllum often requires microscopic examination of the seed cases, beyond the scope of this key.
All native plants on unleased land in the ACT are protected.
PlantNET description: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Myriophyllum~verrucosum (accessed 24 January, 2021)
This identification key and fact sheets are available as a free mobile application:
