East Indian hygrophila

Hygrophila polysperma

Description

Submerged and emergent perennial to 50 cm
tall.

Leaves:

■ Opposite
■ Spear-shaped, 0.7–8 cm long, pointed tips
■ Submerged leaves: longer with small leaf stalk
■ Emergent leaves: slightly rounder with no leaf
stalk
■ Variable leaf colour: bright green to brown to
reddish

Flowers:

■ Small, 0.5–0.6 cm long, bluish-white
■ In emergent leaf axils (stem and leaf junction)
Stems:
■ Emergent: squarish in cross section and
slightly hairy
■ Submerged: round and can grow over 2 m
long

Fruit:

■ Capsule 0.6–0.7 cm long, contains 15–25
seeds

Seeds:

■ Pale brown, round and flattened, 0.08 cm in
diameter
Similar looking species
■ Alligator weed (Alternanthera philoxeroides):
single white ball-like flower on stalk and
hollow stem
■ Hygrophila (Hygrophila costata): leaves up to
18 cm long

Background

East Indian hygrophila is native to South-East
Asia and is found in tropical regions of the world.
It has been used in Australia as an aquarium
plant. It is particularly difficult to control as it
reproduces by stem fragmentation and from leaf
nodes.
Distribution
Widespread in south-eastern Qld and in several
locations on the North Coast of NSW.
Means of spread
East Indian hygrophila can reproduce by
fragments and from leaf nodes, which are spread
by water, and by attaching to boats and fishing
equipment.
Declaration status
NSW: C1(S); WA: Unass.
If found, report this weed to your local weed
authority.


Source: Recognising Water Weeds Plant Identification Guide
Aquatic Weeds Early Detection Project Compiled by Jessica Grantley, Fiona McPherson and
Andrew Petroeschevsky,

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