Myriophyllum amphibium Labill.

Broad Water-milfoil

Nov. Holl. Pl. 2: 70, t. 220 (1806) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Perennial marsh, semi-aquatic or emergent herb; stems mat-forming, rooting at the nodes, tips erect, to 7 cm tall, c. 1 mm diam. Leaves opposite, broad-lanceolate to obovate, with a terminal gland, 5–25 mm long, subfleshy, margins entire or rarely with 1 or 2 lobes or teeth. Bracteoles usually linear to lanceolate, 0.7–0.8 mm long; flowers solitary. Male flowers sessile or shortly pedicellate; sepals 4, lanceolate to oblanceolate or ovate to obovate, 0.8–1 mm long; petals 4, 1.8–2.5 mm long, red; stamens 8. Female flowers sessile; sepals triangular, c. 0.4 mm long; petals absent; ovary 4-celled, styles cylindric, becoming reflexed, stigmas red, fading to white. Fruit cylindric, purplish-black; mericarps more or less tear-drop-shaped, 1.1–1.2 mm long including style, sparsely warty-papillose. Flowers Nov.–Mar.

Brid, EGL, GipP, Glep, GGr, HSF, OtP, VVP, WaP, WPro. Also SA, Tas. Scattered across southern Victoria where it may be found around lakes, along boggy stream margins or in pools along rivers.

Leaf shape is variable and very narrow-leaved forms may be difficult to distinguish from M. pedunculatum.

Source: Jeanes, J.A. (1996). Haloragaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 3, Dicotyledons Winteraceae to Myrtaceae. Inkata Press, Melbourne.
Updated by: Val Stajsic, 2019-01-16
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder [Saxifraganae]
order Saxifragales
family Haloragaceae
genus Myriophyllum
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Myriophyllum amphibium in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Myriophyllum amphibium in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Glenelg Plain present native
Bridgewater present native
Victorian Volcanic Plain present native
Gippsland Plain present native
Otway Plain present native
Warrnambool Plain present native
Greater Grampians present native
East Gippsland Lowlands present native
Wilsons Promontory present native
Highlands-Southern Fall present native

State distribution

Distribution map
South Australia