Paterson’s Curse (PA) | Echium plantagineum
[Boraginaceae]
(Salvation Jane, Lady Campbell Weed, Purple Bugloss,
Riverina Bluebell, etc.)
Location : Located in all states. Declared noxious
weed, except QLD and ACT.
Season: Short-lived Winter annual.
Danger Level: Highly dangerous, usually unpalatable
to horses. All parts of the plant are toxic and the
toxicity is not lost in dried plants. Paterson’s Curse
grows to 90cm. Flowering occurs in early Spring.
TOXIC WEEDS For Horses IN AUSTRALIA
Your guide to toxic weeds for horses in Australia, including where and when they grow.
This document is a basic field guide to
weeds that are toxic to horses in Australia. It’s a
helpful resource that you can keep on file
to identify and protect your horse from
toxin poisoning.
Each weed has a code in brackets at the end
of the name (i.e. Paterson’s Curse PA), which
relates to the type of toxin present.
The different types of toxins are listed at
the end of this document, along with the
symptoms your horse may display if poisoning
has occurred.
Each weed is displayed in a photo for easy
identification, along with information about the
state it grows in, and the time of year it grows
or flowers.
The level of toxicity present in each weed is
also displayed, indicating whether it’s midly,
moderately or highly dangerous to horses.
Horses are very selective when grazing. Most
won’t eat weeds unless there is no other
option (i.e. in drought conditions) or if hay or
feeds given are contaminated.
Some weeds in their dried form are still quite
toxic to horses, so it’s always advisable to
check hay before giving it to horses for any
foreign weeds.
Crotalarias (PA) | Echium plantagineum
[Fabacaeae]
(Kimberly Horse Poison, Grey Rattlepod, Narrowleaf
Rattlepod, Yellow Rattlepod, etc.)
Location : Not in VIC or TAS.
Season: Most species are annual, with some being
perennial. Some species are native.
Danger Level: : Highly dangerous, usually unpalatable
to horses. Plants in Crotalaria genus are known
as ‘rattlepods’ because the seeds rattle inside the
deflated seedpod when shaken. A horse poisoned is
said to be suffering ‘Crotalism’, ‘Walkabout Disease’
or ‘Kimberly Horse Disease’.
Ragwort (PA) | Senecio jacobaea
[Asteraceae]
(Tansy Ragwort, Common Ragwort, Stagger Wort,
Stinking Willy, St James’ Wort, etc.)
Location : Declared noxious weed in VIC, TAS, NSW,
SA and WA.
Season: Long-lived perennial that grows to 1.2m.
Ragwort usually flowers in Summer. The flowers are
bright yellow. The plant gives off an upleasant smell
when damaged.
Danger Level: : Moderate danger
Fireweed | Senecio jacobaea
[Asteraceae]
(Madagascar Ragwort, Senecio Amarillo, etc.)
Location : The plant has spread rapidly in Australia,
particularly in the past 30 years and is a significant
problem for famers. Declared noxious weed in QLD,
NSW, ACT and WA.
Season: Short-lived annual that grows 10-50cm tall.
Danger Level: Moderate danger. Fireweed is native
to southern Africa and Madagascar.
Blue Heliotrope (PA) | Heliotropium
amplexicaule [Boraginaceae]
(Wild Verbena, Clasping Heliotrope, Purpletop,
Turnsole, Wild Heliotrope, Creeping Heliotrope, etc.)
Location : QLD, NSW, VIC and SA. Declared noxious
weed in NSW and WA.
Season: Summer-growing perennial that grows to
30cm. The plant produces a flush of growth from
Autumn to Spring, and flowering usually occurs from
November through Summer and into early Autumn.
Danger Level: Moderate danger.
Common Heliotrope (PA) | Heliotropium
europaeum [Boraginaceae]
(Potato Weed, European Heliotrope, Barooga Weed,
Wanderie Curse, Bishop’s Beard, Caterpillar Weed,
etc.)
Location : Declared noxious weed in WA and TAS,
located in all states.
Season: Short lived annual that grows to 30cm.
Danger Level: Moderate danger.
Heliotropium Ovalifolium (PA) |
[Boraginaceae]
(Heliotropium coromandelianum var. ovalifolium,
Heliotropium gracile, etc.)
Location : WA, NT, QLD and SA.
located in all states.
Season: Perennial that grows 15-80cm.
Danger Level: Moderate danger.
Amsinckias |
[Boraginaceae]
(Amsinckia calycina, Amsinckia lycopsoides,
Amsinckia intermedia and Amsinckia menziesii.)
(Amsinckia, Yellow Burrweeds, Fiddlenecks, etc.) It
is thought these plants may not be separate species,
but different forms of one species.
Location : Declared noxious weeds in VIC, SA and
WA, located in all states.
Season: Short-lived perennial that grows 10-50cm.
Flowering occurs from late Winter to Spring. The
flowers are tube-shaped, and yellow or orange.
Danger Level: Moderate danger.
Blue Canary Grass (TA) |
Phalaris
coerulescens [Poaceae]
Location : NSW, VIC and TAS.
Season: Short-lived perennial that survives for 3-4
years. It grows vigorously in Autumn and Spring,
especially after rain. The grass continues its growth
through Winter and has a Summer dormancy period.
In cool, high rainfall areas, the grass maintains growth
through Summer. Flowering occurs in late Spring.
Danger Level: Highly dangerous.
Paradoxa Grass (TA) |
Phalaris paradoxa
[Poaceae]
Location : Located in all states, except TAS.
Season: Annual. It grows mainly in Winter and
Spring, and can grow vigorously after rain. The seeds
germinate in Autumn to early Winter. Flowering
occurs in late Spring.
Danger Level: Highly dangerous.
Smooth Darling Pea |
Swainsona galegifolia
[Fabaceae]
(Swainsona, etc.)
Location : QLD, NSW, VIC and NT.
Season: Perennial that grows to 1m. The plant
flowers in Spring.
Danger Level: Highly dangerous.
Hairy Darling Pea |
Swainsona greyana
Location : QLD, NSW and SA.
Season: Perennial that grows to 1.5m. The plant flowers in Spring.
Danger Level: Highly dangerous.
Grey Swainsona |
Swainsona canescens
Location : WA, NT, QLD and SA.
Season: Perennial that grows to 60cm or higher in
favourable conditions. The plant flowers from May
through to December.
Danger Level: Highly dangerous.
Broughton Pea |
Swainsona procumbens
Location : QLD, NSW and VIC.
Season: Perennial that grows 30-50cm. The plant
flowers in Spring.
Danger Level: Highly dangerous.
Dwarf Darling Pea |
Swainsona luteola
Location : QLD, NSW and SA.
Season: Perennial that grows to 50cm. The plant
flowers in Spring.
Danger Level: Highly dangerous.
English Yew (TAX) | Taxus baccata
[Taxaceae]
Location : NSW, VIC and TAS.
Season: Evergreen tree that can grow to 20m. The
tree has a dark trunk that is quite thick in mature
plants. It flowers in Spring.
Danger Level: Highly dangerous.
Field Bindweed (TROP) | Convolvulus
arvensis [Convulvulaceae]
(Common Bindweed, Morning Glory, Field Morning
Glory, etc.)
Location : Located in all states. Declared noxious
week in VIC, SA and WA.
Season: The vine flowers in Spring to early Autumn,
with most flowers appearing in Summer.
Danger Level: Moderate danger, however, no cases
of Field Bindweed poisoning have been reported in
Australia.
Thornapples (TROP) | Datura spp
[Solanaceae]
The plants in the Datura genus are commonly known
as thornapples. There are several native thornapples,
but most of the species that grow in Australia were
introduced as garden ornamentals.
Location : Located in all states.
Season: Summer-growing annual. They range in
height from 50cm-2m, but most grow to 1m.
Danger Level: Moderate danger.
Angel’s Trumpet (TROP) | Brugmansia spp
[Solanaceae]
Location : Located in all states, except NT.
Season:Grown in Australia as garden ornamentals
and some species have naturalised in some areas of
Australia. Perennial shrubs or small trees that can
grow to 5m, but most are around 3m.
Danger Level: Low danger.
Poison Corkwood (TROP) | Duboisia
myoporoides [Solanceae]
Location : East coast of Australia, SA and NT.
Season: Native to Australia. Shrub or tree that can
grow to 9m. The bark of the tree is thick and ‘corky’,
and is yellowish-brown to pale grey in colour. Poison
Corkwood flowers in Winter and Spring.
Danger Level: Low danger.
Corkwood (TROP) | Duboisia leichhardtii
[Solanaceae]
(Poisonous Corkwood, Queensland Duboisia, Yellow
Basswood, etc.)
Location : QLD and northern NSW.
Season: Native to Australia. A shrub or tree that can
grow to 7.5m. Corkwood flowers mainly in Winter.
Danger Level: Low danger.
Hemlock (PIP) | Conium maculatum
[Apiaceae] (Fool’s Parsley, Poison Root, Carrot Fern,
Winter Fern, California Fern, Wild Carrot, Wild
Parsnip, Wode Whistle, etc.)
Location :Located in all states, except NT. Declared
noxious weed in VIC, NSW and WA.
Season: Hemlock is rarely grazed. The main danger
is contamination of hay, chaff or feed. Horses may
graze Hemlock if other forage is low. Short-lived
biennial or annual plant that grows 1-2m. The seeds
germinate in Autmn and can grow rapidly after rain.
Danger Level: Highly dangerous.
Lupins (QUIN) | Lupinus spp [Fabaceae]
Several species of lupins grow in Australia; some
as ornamental garden plants and some introduced
lupins have naturalised to become weeds. The lupins
grown for human or livestock feed are low-alkaloid
varieties and do not cause quinolizidine poisoning.
Location :Located in all states.
Season:Can be annual or perennial, and can grow to
1m. Flowering in Summer.
Danger Level: Low danger.
Golden Chain Tree (QUIN) | Laburnum
anagyroides [Fabaceae]
Location : WA, NSW, VIC, SA and TAS. Grown in
Australia as an ornamental garden tree.
Season:Deciduous and it usually grows to around
7m. Flowers from Spring to early Summer. The tree is
known for its distinctive showry yellow flowers.
Danger Level: Low danger.
English Broom | [Fabaceae]
(Scotch Broom, Broom, etc.)
Location : NSW, VIC, SA and TAS. Declared noxious
weed in all states, except NA and QLD.
Season: Upright perennial shrub that usually grows
1-2m, but can grow up to 4m. Flowering usually
occurs from Spring to early Summer, but flowers may
appear at any time throughout the year.
Danger Level: Moderate danger.
Montpellier Broom | Genista monspessulana
[Fabaceae] (Cytisus monspellulanus, Teline
Monspessulana, etc.)
(Cape Broom, Canary Broom, French Broom, Madeira
Broom, Broom, etc.)
Location : Located in all states, except NT. Declared
noxious weed in all states, except NT and QLD.
Season: Upright and spreading shrub that usually
grows 1-2m, but can grow up to 3m. Flowering
usually occurs in late Winter and Spring.
Danger Level: Moderate danger.
Lobelia (PYR) | Lobelia spp [Lobeliaceae]
Around 20 species of native Lobelia grow in Australia.
Location : Located in all states.
Season: Annual or perennial herbs.
Danger Level: Low danger.
Lobelia (PYR) | Lobelia spp [Lobeliaceae]
Around 20 species of native Lobelia grow in Australia.
Location : Located in all states.
Season: Annual or perennial herbs.
Danger Level: Low danger.
Prunus (CYA) | Prunus spp [Amygdalaceae]
Includes plums, peaches, apricots, cherries,
nectarines and almonds. The ingestion of prunus
leaves can be enough to cause poisoning. Toxin levels
are highest when leaves are damaged or stressed
from frost, storms, drought or seasonal whilting.
Location : Located in all states.
Season: Trees or shrubs are mostly deciduous. The
plants produce white or pink blossoms that appear in
Spring before new leaves.
Danger Level: Highly dangerous.
Johnson Grass (CYA) | Sorghum halepense
[Poaceae] (Johnson Grass, etc.)
Distinguishing between different grasses can be
extremely difficult.
Location : Located in all states. Major weed in
pastures and crops. Declared noxious weed in NSW,
NT and WA.
Season: Long-lived perennial grass that can grow
to 1.5m. It reproduces by seed and creeping
underground stems.
Danger Level: Moderate danger.
Sudan Grass (CYA) | [Poaceae]
(Sorghum sudanense, Sorghum drummondii, etc.)
Around 17 species of tobacco grow in Australia.
Location : QLD, NT and WA.
Season: Annual grass and very similar to Johnson
Grass, except no underground shoots and seed head
is longer.
Danger Level: Moderate danger.
Columbus Grass (CYA) | [Poaceae]
May be a hybrid of Sorghum halepense x almum.
Columbus Grass is very similar to Johnson Grass.
Location : QLD and NSW. Declared noxious weed in
NSW and WA.
Season: Annual grass.
Danger Level: Moderate danger.
Grin Sorghum | Sorghum bicolour [Poaceae]
Grain Sorghum is similar to Johnson Grass, but does
not have underground stems.
Location : Located in all states.
Season: Annual or short-lived perennial. The flower
head of Grain Sorghum is denser than Johnson Grass.
Danger Level: Moderate danger.
Spotted Fushsia (CYA) | Eremophila maculata
[Myoporaceae]
(Native Fuchsia, Spotted Emu Bush, etc.)
Location : Located in all states, except TAS.
Season: Perennial shrub that grows to 2m. Flowers in
Winter and Spring. Flowers can be shades of yellow
or red.
Danger Level: Moderate danger.
Birdsfoot Trefoil (CYA) | Lotus corniculatus
[Fabaceae]
(Native Fuchsia, Spotted Emu Bush, etc.)
Location : QLD, NSW, VIC, SA and TAS.
Season: Annual or perennial plant growing to 40cm.
The Spring-Summer flowers are usually yellow with
red veins.
Danger Level: Moderate danger.
Wattles (CYA) | Acacia spp [Fabaceae]
Acacia is the largest genus of flowering plants in
Australia with 960 species.
Location : Located in all states.
Season: Trees or shrubs. Flowers are usually yellow.
Danger Level: Moderate danger.
Couch Grasses (CYA) | Cynodon spp [Poaceae]
Particularly African Star Grass (Coondai Couch),
Cynodon nlemfuensis and Cynodon plectostachyus.
Location : Located in all states.
Season: Perennial.
Danger Level: Moderate danger.
Native Couch (CYA) | Brachyachne
convergens [Poaceae] (Cynodon convergens, etc.)
(Spider Grass, etc.)
Location : QLD, NSW, VIC, WA and NT.
Season: Annual that grows to 50cm.
Danger Level: Moderate danger.
Linseed (Flax) (CYA) | Linum usitatissimum
[Linaceae] Heat pressed linseed meal does not
contain cyanogenic glycosides and is not a risk. Cold
pressed linseed meal that has not been treated with
heat poses some risk to horses.
Location : Located in all states.
Season: Feed supplement.
Danger Level: Moderate danger if incorrectly
processed.
Oleander (CAR) | Nerium oleander
[Apocynaceae] Widely grown in Australia as a garden
ornamental or street tree. The plant is extremely toxic
to all species, including humans. A study has shown
the ingestion of only 7 leaves can be fatally toxic to
an average-sized horse.
Location : Located in all states.
Season: Evergreen shrub or tree that can grow 2-5m.
The plant flowers, but many cultivars can also flower
in Spring and Autumn. Most are pink, but can be
white, red or yellow.
Danger Level: Extremely dangerous.
Yellow Oleander (CAR) | Cascabela thevetia
[Apocynaceae] (Thevetia nereifoila, Thevetia
peruviana, etc.)
(Captain Cook Tree, Cook Tree, Lucky Nut, Mexican
Oleander, Dicky Plant, etc.)
Location : Located in all states. Widely grown as a
garden ornamental. Declared noxious weed in QLD.
Season: Evergreen shrub or tree that can grow
2.5-3m. Occasionally, it can grow to 10m. The plant
flowers mostly in Summer and Autumn, but can
flower any time of year.
Danger Level: Extremely dangerous.
Rubber Vine (CAR) | Cryptostegia grandiflora
[Asclepiadaceae] (Indian Rubber Vine, etc.)
Location : QLD, NT and WA. Declared noxious
weed in QLD, NT, WA and SA. Considered one of
Australia’s worst weeds and is on the list of Weeds of
National Significance.
Season: Woody shrub or climber. Can grow 1-3m
without support, but it can grow to 30m when
growing on vegetation. Flowers mainly in Summer.
The flowers are white, or shades of purple or pink.
Danger Level: Highly dangerous.
Purple Rubber Vine (CAR) | Cryptostegia
madagascariensis [Asclepiadaceae]
(Rubber Vine, Madagascar Rubber Vine, etc.)
Location : QLD, NSW, NT and WA. Declared noxiousweed in QLD, WA and NT.
Season: Same as Rubber Vine above, but flowers are
a deeper shade of pink or purple.
Danger Level: Highly dangerous.
Mother of Millions (CAR) | Bryophyllum spp
[Crassulaceae]
Location :Located in all states, except TAS. Several
species of Bryophyllum have been declared noxious
weeds in QLD, NSW and WA.
Season: Perennial succulents that can grow to 1.8m
Flowering occurs in Winter to early Spring. Flowers
contain the highest levels of toxins and are the most
palatable part of the plant. May be eaten when
fodder is scarce. Sometimes found as a contaminant
of hay.
Danger Level: Highly dangerous.
One Leaf Cape Tulip (CAR) | Moraea flaccida
[Iridaceae]
Location : WA, NSW, VIC, ACT and TAS.
Season: Plant produces perennial underground
‘bulbs’, called corns. Leaves and stems die back
annually. Usually grows to 60cm, but can occasionally
grow to 75cm. The plant flowers in late Winter to
early Spring.
Danger Level: Highly dangerous.
Two Leaf Cape Tulip (CAR) | Moraea miniata
[Iridaceae] Homeria flaccida, Homeria miniata, etc.)
Location : WA, NSW, VIC, ACT and SA.
Season: Plant produces perennial underground
‘bulbs’, called corns. Leaves and stems die back
annually. Usually grows to 60cm. The plant flowers in
late Winter to early Spring.
Danger Level: Highly dangerous.
Cotton Bushes (CAR) | Gomphocarpus spp
[Apocynaceae] (Asclepias spp, etc.)
Known as Milkweeds and some are known as Swan
Plants.
Location : Located in all states. Narrow Leaf Cotton
Bush (Gomphocarpus fruticosus) is declared noxious
weed in WA.
Season: Perennial upright plant that usually grows
1-2m. Flowering can occur from Spring to Autumn.
Danger Level: Highly dangerous.
Foxglove (CAR) | Digitalis purpurea
[Scrophulariaceae]
Location : Located in all states.
Season: Perennial or biennial plant that grows to
around 1.5m. Flowers in Spring to early Summer and
can be white, purple or pink with mottled patterns.
Danger Level: Highly dangerous.
Ornithogalums (CAR) | Ornithogalum spp
[Hyacinthaceae]
Location : Located in all states.
Season: Annual plant, which grows from bulbs.
Flowering occurs mostly in Spring, but can occur at
other times of the year.
Danger Level: Highly dangerous.
Blue Periwinkle (CAR) | Vinca major
[Apocynaceae]
(Greater Periwinkle, etc.)
Location : QLD, NSW, VIC, ACT, WA and TAS.
Season: Perennial that grows to 50cm. Flowering
occurs in Spring and Summer, and are mauve or
purple. Petals have a distinctive ‘twist’.
Danger Level: Highly dangerous.
Pheasant’s Eye (CAR) | Adonis microcarpa
[Ranunculaceae]
(Small Fruited Pheasant’s Eye, Red Chamomile,
Adonis, Autumn Pheasant’s Eye, etc.)
Location : Located in all states. Declared noxious
weed in SA and WA.
Season: Annual that usually grows 20-40cm, but can
occasionally grow to 60cm. The plant flowers in late
Winter to early Summer. The flowers are bright red or
occasionally yellow.
Danger Level: Highly dangerous.
Celery-Leaf Buttercup (PRO) | Ranunculus
sceleratus [Ranunculaceae]
(Poison Buttercup, Cursed Crowsfoot, etc.)
Location : QLD, NSW, VIC, ACT, SA and TAS. Declared
noxious weed in SA and WA.
Season: Annual that usually grows to 60cm.
Flowering occurs in Spring The flower has 5 yellow
petals and 5 hairy bracts that are bent downwards.
Danger Level: Low danger.
Panicum (SPE) | Panicum spp [Poaceae]
Five species of Panicum have been associated with
livestock and these are Giant Panic Grass (Panicum
antidotale), Coolah Grass (Panicum colaratum),
Guinea Grass (Panicum maximum), Millet Panic
(Panicum miliaceum) and Red Switch Grass (Panicum
virgatum).
Location : Located in all states.
Season: Annual or perennial. Distinguishing between
the different panic grasses can be extremely difficult.
Danger Level: Low danger.
Panicum (SPE) | Panicum spp [Poaceae]
Five species of Panicum have been associated with
livestock and these are Giant Panic Grass (Panicum
antidotale), Coolah Grass (Panicum colaratum),
Guinea Grass (Panicum maximum), Millet Panic
(Panicum miliaceum) and Red Switch Grass (Panicum
virgatum).
Location : Located in all states.
Season: Annual or perennial. Distinguishing between
the different panic grasses can be extremely difficult.
Danger Level: Low danger.
