Download Yellow burrhead

NSW DPI
HAVE YOU SEEN THIS PLANT?
Weed
Alert
Yellow
burrhead
(Limnocharis flava)
Yellow burrhead.
Photo: Paul Zborowski, Queensland Department of Natural Resources, Mines and Water
Introduction
Yellow burrhead is an aquatic plant that has
the potential to become a major weed of
wetlands, slow moving streams and dams in
semi-tropical and tropical areas of Australia.
It colonises shallow wetlands and the
margins of deeper waterways where it can
quickly grow to dominate other aquatic
plants. The leaves and stems slow water
movement in channels and drains causing
silt to built up, eventually blocking
water flow.
With unusual foliage and attractive
flowers, yellow burrhead is likely to
be lurking unrecognised in suburban
backyards, especially those featuring ‘
Asian water gardens’.
This plant is banned from entry into
Australia.
World Status
Yellow burrhead is a native of Central
America (from Mexico through to
Paraguay) and the Caribbean Islands. It has
naturalised in the USA, Sri Lanka, India
and south-east Asia including Indonesia,
where it is threatening wetlands and has
become a problematic weed of rice fields
and irrigation channels.
In Asia it has been used as a food source
but severe infestations have forced farmers
to abandon rice paddies.
Several small naturalised populations and
individual plants in garden ponds were
discovered in the Cairns and Townsville
districts in 2001–2002.
Yellow burrhead flower.
Photo: K. Galway, Queensland Department of Natural Resources, Mines and Water
A nationally funded eradication campaign
is currently underway to remove isolated
populations of yellow burrhead in northern
Queensland.
Identification
Yellow burrhead is a perennial herb that
prefers shallow, still water where it roots in
mud. It emerges from the water and grows to
1 m high.
Leaves and stems
Triangular fleshly leaf stalks and flowering
stems grow in clumps from seed or daughter
plants. The leaf stalks are 5–75 cm long and
green. The leaves above the leaf stalk are
broad and oval shaped (5–30 cm long and
4–25 cm wide).
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Flowers
The small, yellow, three-‘petalled’ flowers
grow in clusters of up to 15 at the end of a
stalk. Plants flower all year round.
Fruit and seeds
Each fruit is 2 cm wide and made up of many
crescent-shaped segments. A single fruit can
produce about 1000 seeds. The seeds are dark
brown, horseshoe-shaped, about 1.5 mm
long with obvious ridges.
Growth
Yellow burrhead reproduces both by seed
and vegetatively. It behaves as a perennial in
areas that have year-round wet conditions
and as an annual in areas that endure dry
seasons. It thrives in nutrient-enriched water
and multiplies rapidly.
This prolific seed producing plant is capable
of producing 1 million seeds per year. After
fruiting, the flower stalk bends towards the
water and releases the fruit onto the surface.
The fruit eventually split into segments that
float to new locations and these segments
then break down to release seeds.
Plantlets develop after a flowering stem
looses all of its flowers and bends over into
the mud. The end of the stem then takes root
in the mud below or breaks off and floats
away to form new infestations.
Watch out for and report Any
form of Yellow burrhead:
If you have seen this
plant, please report
it to your Council
Weeds Officer or NSW
Department of Primary
Industries for positive
identification.
Prepared by Annie Johnson, Weeds Project
Officer, Orange and Rachele Osmond, Weeds
Project Officer, Tamworth.
6888
Limnocharis flava is���a Class
������ 1
�� noxious
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weed throughout NSW under the
NSW Noxious Weeds Act 1993. This
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weed must be eradicated from the
land and the land must be kept free
of the plant. As a notifiable weed, all
outbreaks must be reported to the
local council within three days.
Yellow burrhead flower and buds.
Photo: K. Galway, Queensland Department of Natural Resources, Mines and Water
Visit our website: www.dpi.nsw.gov.au/weeds