Important Poisonous Vascular Plants of Australia


TABLE 05: Important Poisonous Vascular Plants of Australia

Scientific and Common Names^*	Plant Characteristics	Habitat and Distribution^†	Affected Animals	Toxic Principle and Effects	Comments and Treatment^‡
* Abrus precatorius Gidee-gidee, Rosary pea, Precatory bean, Jequirity bean, Crab’s eye	Vine with compound leaves and sprays of pink pea-type flowers followed by curled pods containing red and black seeds	Widespread in tropical Australia	Ruminants, horses, humans	Abrin (toxalbumin) causing severe gastroenteritis	Seeds are the toxic part of the plant. No effective treatment is known.
Acacia georginae Georgina gidyea	Small tree with dark gray fissured flaky bark, “leaves” (phyllodes) gray-green tapered at both ends with parallel veins and clusters of yellow fluffy globular flowers in the “leaf” forks followed by flat curved and coiled seed pods	Arid zone; eastern central Australia	Cattle, horses, dogs (secondary poisoning)	Fluoroacetate—sudden death. Dogs scavenging carcasses of poisoned livestock can be poisoned.	Pods and young foliage are most toxic. No effective treatment is known.
* Adonis microcarpa Pheasant’s eye	Annual herb with highly divided (ferny) leaves and glossy scarlet 5- to 8-petalled flowers	Weed of cultivation in temperate regions	Ruminants, horses, pigs	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Both seeds and whole plants have caused toxicity. Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
* Ageratina (Eupatorium) adenophora Crofton weed	Shrub with numerous upright stems 1-2 m high; leaves opposite and trowel-shaped; white flowers in dense clusters at ends of stems	Naturalized weed of pastures in eastern coastal regions	Horses	Unidentified toxin causes coughing and decreased exercise tolerance progressing to dyspnea from chronic pulmonary inflammation and fibrosis. Heart failure occurs in some cases.	Flowering plants are the most toxic. No effective treatment is known.
Agrostis avenacea Blown grass, Blow-away grass	Grass, tufted with spreading seedhead	Coastal and inland areas of subtropical and temperature regions	Ruminants, horses	Corynetoxins (tunicaminyluracils produced by Rathayibacter toxicus bacteria in seedhead nematode galls) cause “floodplain staggers” with convulsions and death in most cases. See .	Corynetoxins—a cyclodextrin toxin binding agent is under development as an antidote. Immunization is being developed for prevention.
Alstonia constricta Bitter bark, Quinine tree	Tree up to 12 m, frequently suckering to form thickets; corky bark; leaves opposite; milky sap; cream, star-shaped flowers in clusters at ends of branches; long narrow pods with seeds bearing silky hair tufts	Widespread in coastal and inland southern Queensland and northeastern New South Wales	Ruminants; dogs may be poisoned by meat from poisoned ruminants.	Indole alkaloids (alstonine, alstonidine)—tetanic spasms of skeletal muscles	Leaves and fruit are toxic. Deny further access to plants. Serious cases may benefit from heavy sedation.
* Ammi majus Bishop’s weed	Annual herb with upright stems, ferny leaves and small white flowers in flat-topped clusters	Weed of cultivation in temperate regions	Ruminants, horses	Furanocoumarins—primary photosensitization, including corneal edema	Supportive therapy for photosensitization (shade, anti-inflammatory, rehydration). No specific therapy available. Deny further access to plants.
* Anthoxanthum odoratum Sweet vernal grass	Grass, tufted upright with tapered cylindrical seedhead	Coastal and subcoastal in temperate regions. A weed of pasture.	Cattle	Dihydroxycoumarin produced in moldy hay or silage causes coagulation defects and extensive hemorrhage in affected animals.	Toxin will be transported across the placenta and through milk. Treat with vitamin K₁ injections.
^* Arctotheca calendula Cape weed	Annual herb with leaves in rosette; hairy on lower surfaces; bright yellow daisy-type flowers with dark centers	Weed of cultivation in southern regions	Ruminants	Nitrates—methemoglobinemia	Toxicity is most likely from rapid large plant intakes. Nitrates—IV methylene blue.
^* Argemone spp Mexican poppies	Upright thistle-like herbs with variegated gray-green deeply divided spiny leaves, large pale or deep yellow 4- to 6-petalled flowers followed by seed capsules with small dark seeds; cut stems exude bright yellow sap.	Widespread weeds of cultivation	Poultry, ruminants	Isoquinoline alkaloids cause heart failure with cardiomyopathy, pulmonary and subcutaneous edema.	Seeds are the most toxic part, but dry plants in hay may be toxic. No effective treatment is known. Seeds crushed and ex-posed to sunlight are detoxified.
* Asclepias curassavica Red-head cotton-bush, Red cotton	Shrub with upright stems, milky sap, simple tapered leaves, red and yellow flowers and tapered seed pods with tufted seeds	Weed of pasture and cultivation in northern regions	Cattle	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
Atalaya hemiglauca Whitewood	Small tree <6 m high with pale gray flaky bark with compound leaves consisting of 1-3 pairs of narrow leaflets and cream flowers in bunches at the end of branches, followed by winged fruit	Inland regions of mainland states	Horses	Unidentified toxin. A syndrome of cardiac failure is reported with severe edematous swelling of the head, muscle weakness, and myoglobinuria.	Young shoots and fruit are regarded as the toxic parts. Poisoning occurs when the plant forms a large proportion of the diet. No effective treatment is known.
* Avena sativa Oats	Grass, upright	Crop in temperate and subtropical areas	Ruminants	Nitrates—methemoglobinemia. Unknown toxin in “rusty” or “red-tipped” fodder oats causes transient hyperesthesia and diarrhea in cattle. Unknown photosensitizing toxin	Nitrate toxicity is most likely from rapid large plant intakes. Nitrates—IV methylene blue. Supportive therapy for photosensitization (shade, anti-inflammatory, rehydration). No specific therapy available.
Bowenia spp Byfield “fern”, Zamia “fern” There are 2 species, both endemic to Australia.	Fern-like plants with groups of leathery highly-divided leaves arising from underground trunks. Sexes are separate, bearing cones at the apex of the plant.	Open forests and rainforests of northeastern Australia; cultivated in gardens	Cattle	Unidentified neurotoxin—permanent spinal cord degeneration with posterior ataxia in cattle (“zamia staggers”). Methylazoxymethanol—liver necrosis	Seeds and young leaves are the most toxic parts. No effective treatment is known.
* Brachiaria spp Signal grass, Para grass	Grasses, tufted or sprawling	Cultivated tropical pasture grasses	Ruminants, horses	Steroidal saponins—hepatogenous photosensitization in ruminants. Calcium oxalate crystals deny calcium to horses producing nutritional secondary hyperparathyroidism (lameness, weight loss, jaw swelling).	Supportive therapy for photosensitization (shade, anti-inflammatory, rehydration). No specific therapy available. Calcium oxalate (horses)— remove from the pasture and remineralize bones by feeding a mineral supplement with a Ca:P ratio of 2:1, 2 kg/horse/wk for 6 mo.
Brachyachne spp Native couches	Grasses, sprawling or erect with digitate seed heads	Native pasture grasses of northern inland regions	Ruminants	Cyanogenic glycosides— sudden death	Toxicity is most likely from rapid large plant intakes. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat treatment may be needed for relapse.
* Brunfelsia spp Francisia, Yesterday-today-and-tomorrow	Shrub with dense foliage and conspicuous broad flowers opening purple and fading to white and followed by brown to black berries	Cultivated garden plant	Dogs	Unidentified toxin causing vomiting, diarrhea, muscle tremors, and clonic/tonic convulsions	Fruits are toxic. Dogs attracted to ripe fruits will eat large amounts. Treat with an emetic followed by oral activated charcoal, 1-3 g/kg plus a saline cathartic, with an anticonvulsant or anesthetic to treat seizures.
* Bryophyllum (Kalanchoe) spp Mother-of-millions	Erect succulent herbs with fleshy leaves (pencil-shaped to broad and lobed depending on species) and clusters of hanging tubular flowers with red petals at the top of stems	Naturalized weedy garden escape of north-eastern regions; prefers shaded habitat on leaf litter	Cattle	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Flowering plants are most toxic and poisoning cases are confined to winter when the plants flower. Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol.
* Cascabela thevetia (Thevetia peruviana) Yellow oleander	Shrub or small tree; tapered leaves; bright yellow trumpet-shaped flowers; fleshy fruit turning black when ripe	Cultivated garden plant; naturalized in some areas	Cattle, horses	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
Castanospermum australe Black bean	Tree, usually up to 20 m high with compound leaves and clusters of red and yellow pea-type flowers on branches, followed by large seed pods containing large fleshy brown seeds	Riverine forest of eastern Australia; sparingly cultivated	Cattle, horses	Unidentified toxin causing GI tract irritation; castanospermine (polyhydroxy alkaloid), a glucosidase inhibitor, is not responsible for poisoning.	Toxicity only occurs with persistent consumption of large numbers of ripe seeds, most likely under drought conditions. No effective treatment is known.
* Cenchrus ciliaris Buffel grass	Grass, tufted forming tussocks with crowded seedheads containing numerous bristly spikelets	Naturalized tropical pasture grass; weedy in arid zone	Ruminants, horses	Soluble oxalates—hypocalcemia, nephrosis in ruminants but not horses. Calcium oxalate crystals deny calcium to horses, producing nutritional secondary hyperparathyroidism (lameness, weight loss, jaw swelling).	Ruminants are susceptible only if very hungry and have access to very lush grass. Soluble oxalates—calcium borogluconate injection (prognosis guarded). Calcium oxalate (horses)—remove from the pasture and remineralize bones by feeding a mineral supplement with a Ca:P ratio of 2:1, 2 kg/horse/wk for 6 mo.
* Cestrum parqui Green cestrum	Multistemmed erect shrub with leaves tapered at both ends and clusters of tubular yellow flowers at the end of stems, followed by black berries	Cultivated garden plant; naturalized in eastern Australia	Ruminants	Diterpenoid (kaurene) glycosides parquin and carboxyparquin cause acute coagulation necrosis of periacinar hepatocytes with rapid death after hepatoencephalopathy in some cases	No effective treatment is known.
Cheilanthes sieberi Mulga fern	Small upright fern with dark stems and small leaves. A xerophytic (drought-resistant) fern, often the first green plant available in pasture after drought-breaking rains	Widespread in woodlands of inland and coastal parts of subtropical and temperate regions	Cattle, sheep	Ptaquiloside (see Pleridium above). Thiaminase (see Marsilea below).	Ptaquiloside—no effective treatment is known. Thiaminase—IV thiamine (vitamin B₁) is effective.
* Citrullus spp Colocynth, Pie melons * Cucumis spp Paddy melons	Vines with yellow flowers and melon-like fruit	Widespread weeds of inland arid regions	Cattle	Cucurbitacins—irritation of the upper GI tract and increased permeability of blood vessels producing sudden death with diarrhea	Ripe fruits are the most toxic part of the plants. Poisoning occurs when cattle have access to large quantities. No effective treatment is known. Rumenotomy to remove fruits could be considered.
* Corchorus olitorius Jute	Erect annual herb with alternate leaves, each bearing 2 elongated basal stipules, yellow 5-petalled flowers, dark cylindrical seed pods	Weed of cultivation and pasture in northern Australia	Cattle, horses, pigs	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Seeds are toxic as contaminants of fed grains. Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
Crotalaria spp Rattlepods	Herbs to shrubs with either simple or trifoliate leaves and bright yellow pea-type flowers on spikes, followed by inflated seedpods	Native and naturalized in subtropical and tropical areas; some species are weeds of cultivation and pasture.	Ruminants, horses, pigs	Pyrrolizidine alkaloids—chronic hepatopathy causing weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle). Rarely, horses may develop pulmonary adenomatosis and severe dyspnea after eating certain species that contain monocrotaline and similar pneumo-toxic alkaloids. Pigs develop nephrosis rather than hepatopathy. Unknown toxin(s) in C aridicola and C medicaginea causes severe esophageal ulceration in horses.	15 species have been associated with toxicity of animals in Australia. Pigs have been poisoned by C retusa seeds contaminating feed grain. No effective treatment for hepatotoxicity. If a stomach tube can be passed in cases of esophageal ulceration, affected horses should recover with symptomatic treatment. See .
* Cryptostegia grandiflora Rubber vine	Vine, multistemmed with oval leaves, pink trumpet-shaped flowers and rigid paired pods	Weed of pasture in northeastern regions	Cattle, horses	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death	Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
* Cupressus macrocarpa Monterey cypress	Tree, densely branched with dark green foliage to 20 m high	Cultivated in temperate areas, often as windbreak trees	Cattle	Isocupressic acid and/or vasoactive lipids—abortion/premature birth	No effective treatment is known. Separating livestock from windbreaks by fencing provides effective prevention.
Cycas spp Zamias, zamia “palm” 27 species endemic to Australia. * C revoluta Sago “palm” from the Japanese islands is cultivated in gardens.	Tree-like plants with trunks surmounted by rosettes of leathery leaves with numerous leaflets. Sexes are separate. Male cones produced at the apex; female cones divided into separate leaf-like structures bearing naked seeds on their margins.	Open forest and woodlands of northern Australia, mostly coastal to subcoastal; some cultivated in gardens	Cattle, dogs	Unidentified neurotoxin causing permanent spinal cord degeneration with posterior ataxia in cattle (“zamia staggers”). Methylazoxymethanol—liver necrosis. Dogs eating seeds of cultivated specimens of C revoluta have been affected.	Seeds and young leaves are the most toxic parts. No effective treatment is known.
Dactyloctenium radulans Button grass	Grass, spreading from central tuft with spikelets in star-like clusters	Widespread native pasture grass in all mainland states	Cattle, sheep	Nitrates—methemoglobinemia	Dangerous only when growing in heavily fertilized soils such as in stockyards and available to hungry animals. Nitrates—IV methylene blue
Dendrocnide spp Stinging trees	Shrubs to trees with broad heart-shaped leaves bearing numerous stinging hairs with small flowers in bunches, followed by fleshy fruits	Rainforests of northeastern regions	Horses, humans	Moroidin (a bicyclic octapeptide) is thought at least partly responsible for intense and persistent local pain caused by contact with stinging hairs on the leaf surfaces. Horses can be driven to frenzy by contact. Pain in humans can persist for several weeks after contact.	No effective treatment is known. Prompt euthanasia should be considered in affected horses.
Duboisia hopwoodii Pituri	Shrub, up to 3 m high with long narrow leaves and groups of white bell-shaped, purple-striped flowers at ends of branches, followed by black berries	Arid regions from central Australia to the western coast	Ruminants	Nicotine causing incoordination, muscle tremors, dilated pupils (impaired vision), recumbency, clonic seizures, diarrhea.	No effective treatment is known. Affected animals left undisturbed often recover.
Duboisia myoporoides and D leichhardtii Corkwoods	Small trees with corky bark with simple leaves and white tubular flowers in bunches at branch ends, followed by black berries	Coastal and inland eastern Australia	Ruminants, horses	Tropane alkaloids causing dilated pupils (impaired vision), tachycardia, convulsions; paralytic ileus or impaction colic, gastric rupture, and hemorrhagic gastroenteritis are reported in horses.	Physostigmine
* Echium plantagineum Patterson’s curse, Salvation Jane	Annual herb with rosette of broad hairy leaves and erect flowering stalk with blue flowers crowded along one side of the curled spikes at the end of the branches	Weed of cultivation and pasture in southern regions	Cattle, horses, sheep	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive waling (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known.
Eremophila maculata Spotted emu bush	Densely branched shrub, 1-2 m high with dark green tapered leaves and red tubular flowers with spotted throats carried on S-shaped stalks, followed by round hard fruits with papery skin	Inland regions of mainland states	Ruminants	Cyanogenic glycosides— sudden death	Young leaves are the most toxic part of the plant. Toxicity is most likely from rapid large plant intakes. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg, plus an oral dose (30 g cattle, 5 g sheep). Repeat for relapses.
Eremophila (Myoporum) deserti Ellangowan poison bush, Turkey bush and M accuminatum Boobialla	Shrubs or small trees with leaves tapered at both ends and small white bell-shaped flowers, hairy inside, followed by purple, black, or yellow berries	Inland regions of mainland states	Ruminants	Furanosesquiterpenes cause acute coagulation necrosis of hepatocytes with rapid death after hepatoencephalopathy in some cases.	Some individual plants are nontoxic. No effective treatment is known.
Erythrophleum chlorostachys Cooktown ironwood, Camel poison	Tree, up to 15 m with compound leaves consisting of leaflets with unequal amounts of blade on either side of the midvein, flower spikes with yellow-green flowers, followed by dry brown flat seed pods	Open woodland in northern Australia	Ruminants, horses	Diterpenoid alkaloids and cinnamic acid derivatives; produce sudden death with effects similar to those of cardiac glycosides.	All parts can be fatally toxic in small doses. Suckers accessible to grazing animals. No effective treatment is known, but the regimen for cardiac glycosides could be applied, eg, oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
Eucalyptus cladocalyx Sugar gum	Tree, up to 30 m with white or yellow-brown smooth bark, adult leaves strongly different shade of green on upper and lower surfaces (discolorous), rubbed buds, white flowers and barrel-shaped fruit	Southeastern states; commonly grown as windbreaks	Ruminants	Cyanogenic glycosides— sudden death	Young leaves are the most toxic part of the plant. Toxicity is most likely from rapid large plant intakes. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat for relapses.
Euphorbia spp Spurges	Prostrate to erect succulent herbs with milky sap and unusual inflorescences (cyathiums)	Toxic species occur in inland areas	Ruminants	Irritant toxins of uncertain identity—alimentary tract irritation, diarrhea. Cyanogenic glycosides suspected in some species—sudden death	Toxicity is most likely from rapid large plant intakes. Irritant toxins—no effective treatment is known. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat for relapses.
Gastrolobium spp Poison bushes	Shrubs, most with opposite leaves or leaves in rosettes around stems, terminal racemes of pea-type flowers with red and yellow or all-red petals, followed by small hairy seed pods	Most species are concentrated in shrublands or southwestern Australia with one species in central and northeastern Australia	Ruminants, horses, dogs (secondary poisoning)	Fluoroacetate—sudden death. Dogs scavenging carcasses of poisoned livestock can be poisoned.	34 species are toxic and 8 more are suspected as toxic. No effective treatment is known.
* Glyceria maxima Reed sweet grass	Grass, erect 90-250 cm high, with an open branched seedhead	Temperate regions in semiaquatic habitats such as on the margins of water storage dams	Ruminants	Cyanogenic glycosides— sudden death.	Cyanide toxicity is most likely from rapid large plant intakes, eg, by hungry animals. cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat treatment may be needed for relapses.
* Gomphocarpus spp Balloon cotton	Shrub with upright stems, milky sap, simple tapered leaves, white flowers, and inflated seed pods with tufted seeds	Weed of pasture and cultivation in northern regions	Cattle	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death.	Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics
* Heliotropium europaeum Common heliotrope H amplexicaule Blue heliotrope	Annual herbs with branched stems bearing green to gray-green simple leaves and flowering stems with white ( H europaeum) or blue (H amplexicaule ) flowers crowded on one side of the curled spikes at the ends of branches	Weeds of cultivation and pasture in southern regions	Cattle, horses, pigs, sheep, poultry	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle).	Seeds of H europaeum contaminating feed wheat have poisoned pigs and poultry. No effective treatment is known.
Heterodendron oleifolium Boonaree, Rosewood, Bullock bush	Tree, up to 7 m high with dark gray furrowed and flaky bark, pale green inconspicuous flowers, followed by rounded fruits	Inland regions of mainland states	Ruminants	Cyanogenic glycosides— sudden death.	The plant is regarded as safe fodder unless fed in large amounts during droughts. Toxicity is most likely from rapid large plant intakes. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat for relapses.
^* Homeria flaccida One-leaf cape tulip; H miniata* Two-leaf cape tulip	Herbs growing from underground corms, forming a leaf or leaves and branched flowering stems with 6-petalled, salmon-pink flowers	Naturalized in temperate regions of southern Australia	Ruminants, horses	Cardiac glycosides—cardiac arrhythmias, diarrhea with blood, dyspnea, sudden death.	Toxicity has occurred from access in pasture or in hay. Cardiac glycosides—oral activated charcoal, 5 g/kg with electrolyte replacement solution; treat arrhythmias with atropine and propranolol; horses should receive analgesics/antispasmodics.
Hoya australis Wax flower	Vine with fleshy round leaves, milky sap, and bunches of waxy white flowers	Rocky areas and vine forests (“dry” rainforests) in coastal and subcoastal Queensland and New South Wales	Cattle, sheep	Unidentified neurotoxin—muscle tremors, ataxia, collapse, clonic/tetanic convulsions	No effective treatment is known.
Indigofera linnaei Birdsville indigo, 9-leaved indigo	Prostrate herb with compound leaves and tight clusters of scarlet, pea-type flowers followed by hairy seed pods	Widespread in tropical Queensland, Northern Territory and Western Australia	Horses, dogs (secondary poisoning)	Probable nitrotoxin causing lethargy, spinal cord damage and posterior ataxia in horses. Indospicine residues in horse meat has caused severe hepatopathy in dogs.	Horses are poisoned when the plant forms a dominant part of pastures in inland areas and is grazed for several weeks. No specific effective treatment is known, but horses drenched with gelatine in warm water, 450 g/kg for 3 days improved. Fencing off the plant, heavy grazing by small ruminants or feeding horses good quality lucerne hay, peanut meal, or cotton seed meal can prevent cases.
* Ipomoea batatus Sweet potato	Vine with arrowhead-shaped leaves and trumpet-shaped pink flowers	Cultivated crop	Ruminants	Pneumotoxic furanoterpenes (3-substituted furans)—severe dyspnea from interstitial pneumonia and edema	Only moldy tubers are toxic. Removal of moldy tubers from the feed results in recovery in most affected animals.
Ipomoea muelleri Poison morning glory	Vine with arrowhead-shaped leaves and trumpet-shaped pink flowers	Central and northwestern regions	Ruminants, horses	Unknown toxin, probably calystegines—incoordination, nervous derangement	No effective treatment is known.
Ipomea calobra Weir vine	Vine with arrowhead-shaped leaves and trumpet-shaped pink flowers	Localized to clay soils of Maranoa district, Queensland	Ruminants, horses	Calystegines, swainsonine—acquired lysosomal storage of mannose leading to incoordination, nervous derangement, weight loss, polyuria.	Animals are reputed to develop a craving for the plants. Toxicity requires access for 4 wk or more. No effective treatment is known. Less severely-affected animals recover if access is prevented.
Isotropis spp Lamb poisons, Granny bonnets, Poison sage	Shrubs or herbs with pea-type flowers with conspicuous radiating branched lines on the back of the large erect standard petal; flowers are purple, yellow, or orange	Most species confined to southwestern Australia with one in central Australia	Ruminants	Iforrestine (heterocyclic alkaloid)—nephrosis.	No effective treatment is known.
^* Jatropha spp	Shrubs and small trees with inconspicuous or bright red flowers and seed pods	Cultivated garden plants, some species are naturalized and weedy in northern Australia	Ruminants, horses	Irritant toxins of uncertain identity—alimentary tract irritation, diarrhea.	No effective treatment is known.
* Lamium amplexicaule Dead nettle	Erect herb up to 30 cm high with opposite, rounded, lobed leaves on square stems and tubular pinkish flowers subtended by cup-shaped leaves around the stem	Widespread weed of cultivation	Ruminants, horses	Unidentified toxin causing incoordination.	Removal from access to plants will result in recovery in most cases.
Leiocarpa (Ixiolaena) brevicompta Flat billy buttons, Plains plover daisy	Low-growing shrub up to ~30 cm tall with numerous flat-topped, dense yellow flower heads	Heavy clay soils of the floodplains of the Darling river system in Queensland and New South Wales	Sheep	Crepenynic acid and other fatty acids cause striated muscle degeneration manifest as sudden death, severely reduced exercise tolerance, muscle weakness and recumbency.	Toxicity is from eating mature seedheads in quantity. No effective treatment is known. Affected sheep will recover in some cases.
Lepidozamia spp Zamias There are 2 species, both endemic to Australia, 1 commonly cultivated in gardens.	Tree-like plants with trunks surmounted by rosettes of leaves with numerous leaflets. Sexes are separate, bearing cones at the apex of the plant.	Open forests and rainforests of northeastern Australia; cultivated in gardens	Cattle	Unidentified neurotoxin— permanent spinal cord degeneration with posterior ataxia in cattle (zamia staggers). Methylazoxymethanol—liver necrosis	Seeds and young leaves are the most toxic parts. No effective treatment is known.
^* Leucaena leucocephala	Shrub to small tree with bipinnate (fern-like) leaves, pale yellow globular flowers, followed by long flat brown seed pods	Cultivated and naturalized browse shrub in tropical regions; weedy in some situations	Ruminants, horses	Mimosine and derivatives—hair loss (ruminants, horses); goiter, cataracts and buccal erosions (ruminants)	No effective treatment is known. Ruminal bacterium ( Synergistes jonesii ) detoxifies mimosine and derivatives. Detoxification capacity is retained as long as mimosine is in the diet, the bacteria surviving up to 9 mo after access stops. Ferrous sulfate supplementation may help monogastric animals.
^* Lolium perenne Perennial ryegrass	Grass, tufted with flattened, flowering spike with spikelets arranged in a zig-zag pattern	Cultivated temperate pasture grass	Ruminants	Lolitrems (tremorgenic mycotoxins from the endophytic fungus Neotyphodium lolii cause perennial ryegrass staggers (muscle tremor, head bobbing/weaving, stiff high-stepping gait, collapse, recovery if undisturbed). Nitrates—methemoglobinemia.	Lolitrems are concentrated in leaf sheaths, making toxicity most likely on well-cropped pasture. No effective therapy available. Nitrates—IV methylene blue. See Rodenticide Poisoning: Introduction.
^* Lolium rigidum Annual ryegrass	Grass, tufted with flattened, flowering spike with spikelets arranged in a zig-zag pattern	Cultivated temperate pasture grass; naturalized weed in southern Australia	Ruminants, horses	Corynetoxins (tunicaminyluracils produced by Rathayibacter toxicus bacteria in seedhead nematode galls) cause annual ryegrass toxicity with convulsions and death in most cases. Ergot alkaloids when seeds infested by Claviceps purpurea (rye ergot) cause agalactia and hyperthermia in pigs and cattle fed grain contaminated with ergot bodies.	Corynetoxins—a cyclodextrin toxin binding agent is under development as an antidote. Immunization is being developed for prevention. Ergot alkaloids—dopamine antagonists may be helpful, domperidone, metaclopromide, reserpine. See Rodenticide Poisoning: Introduction .
Lotus spp Birdsfoot trefoils	Herbs with compound leaves consisting of 5 leaflets, 3 at the tip and 2 at the base and pea-type flowers with red, yellow, pale pink, or white petals	Subtropical and temperate regions in all states	Ruminants	Cyanogenic glycoside— sudden death	Toxicity is most likely from rapid large plant intakes. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat for relapses.
^* Lupinus spp Lupines	Robust herbs with compound leaves with radiating leaflets and flower spikes crowded with pea-type yellow, white, or blue flowers, followed by hairy seed pods	Cultivated grain crops in southern regions	Ruminants	Phomopsins produced by the fungus Diaporthe toxica growing in dead plants—chronic hepatopathy causing weight loss and jaundice with photosensitization in some cases and myopathy in others.	Most toxicity occurs if dry lupine stubble is grazed after grain harvest. No effective treatment is known. Selenium/vitamin E may help myopathy cases. Immunization against phomopsins is being developed as a control measure.
^* Lythrum hyssopifolia Lesser loosestrife	Herb with ribbed stems and simple small leaves with single pink to purple tubular flowers in leaf axils	Weed of pasture in temperate areas	Sheep	Unidentified toxin causing renal tubular and hepatocyte necrosis	Poisoning commonly occurs when sheep are grazed on crop stubbles in which the plant is dominant. No effective treatment is known.
Macadamia spp	Trees with oblong leaves carrying a few marginal spines, and hanging sprays of cream flowers, followed by a globular fruit containing a hard brown nut	Cultivated tree; nuts harvested as food	Dogs	Unidentified toxin; produce muscular weakness and joint pain	Both fresh and roasted kernels are potentially toxic. Clinical signs are transient with recovery occurring within 24 hr, with or without symptomatic treatment. See Macadamia Nuts .
Macrozamia spp Zamias, Burrawang, Zamia “palm” There are ~40 species, all endemic to Australia.	Tree-like plants with trunks surmounted by rosettes of leathery leaves with numerous leaflets. Small species have no trunks. Sexes are separate, bearing cones at the apex of the plant.	Open forests and woodlands of southern and central Australia; some cultivated in gardens	Cattle, sheep (rare), dogs	Unidentified neurotoxin— permanent spinal cord degeneration with posterior ataxia in cattle (zamia staggers). Methylazoxymethanol— animals eating seeds of cultivated specimens of M riedlei have been affected.	Seeds and young leaves are the most toxic parts. No effective treatment is known.
^* Malva parviflora Marsh or small flowered mallow	Herb with rounded 7-lobed pleated leaves on stalks and with white to very pale pink or lavender flowers in clusters in the leaf forks, followed by button-shaped fruit	Widespread weed of cultivation	Ruminants, poultry	Unidentified toxin causing skeletal muscle necrosis. Nitrates—methemoglobinemia. Malvic acid causes pink discoloration of egg whites and pasty yolks from hens eating seeds (or leaves)	Toxicity is most likely from rapid large plant intakes. Nitrates—IV methylene blue.
Marsilea drummondii Common nardoo	Aquatic fern; fronds with 4 leaflets; spores in hairy capsules at ground level	Widespread on floodplains in inland regions of eastern states and in coastal subtropical western Australia	Sheep, horses	Thiaminase—polioencephalomalacia in sheep; “bracken staggers” in horses	The plant contains 100 times more thiaminase than bracken. Poisoning occurs when stock graze dried floodplains dominated by nardoo. IV thiamine (vitamin B₁) is effective in many cases.
^* Medicago spp Medics, Lucerne	Herbs with trifoliate leaves and small yellow or bluish pea-type flowers, followed by twisted seed pods	Subtropical and temperate regions in all states	Ruminants	Unidentified photosensitizing toxin. Phytoestrogens—infertility (rare)	No effective treatment is known.
Melia azedarach australasica White cedar	Deciduous tree with compound leaves, sprays of lilac flowers, followed by clusters of oval yellow fruits	Native to tropical and subtropical rainforest; cultivated garden plant, street and shade tree	Pigs	Tetranortriterpenes cause severe gastroenteritis	Fruits are the toxic part of the plant. Some individual trees are nontoxic. No effective treatment is known.
^* Mesembryanthemum spp Ice plants	Succulent prostrate herbs	Cultivated in gardens; naturalized in southwestern Australia	Ruminants	Soluble oxalates— hypocalcemia, nephrosis	Toxicity is most likely from rapid large plant intakes, eg, by hungry animals. Soluble oxalates—calcium borogluconate injection (prognosis guarded).
Morinda reticulata Mapoon, Adaa	Shrub with stems either self-supporting or scrambling over adjacent plants with leathery, opposite-paired leaves and groups of small flowers with a prominent large white leaf-like bract immediately below	Open woodland of Cape York peninsula	Horses	Selenium as selenoamino acids—hair loss from mane and tail, lameness with cracking and shedding of hooves in severe cases	No effective treatment is known.
Neobassia proceriflora Soda bush	Annual upright many branched small shrub with red striped stems and short blue-green succulent leaves	Inland areas of eastern and central states	Ruminants	Soluble oxalates— hypocalcemia, nephrosis	Toxicity is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded).
Neptunia amplexicaulis Selenium weed	Prostrate herb with compound leaves with a leaf-like, heart-shaped stipule at the junction of leaf stalk and stem and with small yellow globular flowers on stiff stalks, followed by clusters of dark brown seed pods	Native to Richmond-Hughenden area of northern Queensland	Horses, ruminants (rare)	Selenium as selenoamino acids—hair loss from mane and tail; lameness with cracking and shedding of hooves in severe cases	No effective treatment is known.
Nicotiana spp Native tobaccos	Erect herbs with soft dull green leaves and tall flower spikes with tubular white flowers, followed by thin-walled pods	Mostly inland regions of all mainland states	Ruminants	Nicotine causing incoordination, muscle tremors, dilated pupils (impaired vision), recumbency, clonic seizures, diarrhea.	No effective treatment is known. Affected animals left undisturbed often recover.
^* Oxalis pes-caprae Soursob	Perennial prostrate herb with trifoliate spotted leaves and clusters of bright yellow, tubular, 5-petalled flowers on stalks	Widespread weed of pasture and cultivation in temperate areas	Ruminants	Soluble oxalates—hypocalcemia, nephrosis. Chronic intake causes chronic nephrosis and kidney failure.	Toxicity is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded). No effective treatment is known for chronic toxicity.
Panicum spp There are ~30 native and ~10 introduced species in Australia.	Grasses, tufted with open seed heads with spikelets attached on individual stalks	Native and naturalized pasture grasses, tropical to temperate regions	Ruminants, horses	Steroidal saponins cause hepatogenous photosensitization in ruminants. Calcium oxalate crystals deny calcium to horses, producing nutritional secondary hyperparathyroidism (lameness, weight loss, jaw swelling).	Supportive therapy for photosensitization (shade, anti-inflammatory, rehydration). No specific therapy available. Calcium oxalate (horses)—remove from the pasture and remineralize bones by feeding a mineral supplement with a Ca:P ratio of 2:1, 2 kg/horse/wk for 6 mo.
^* Paspalum spp	Grasses, tufted with erect branched seedhead	Cultivated tropical to subtropical pasture grass	Ruminants, horses	Paspalitrems from Claviceps paspali ergots in seedheads—muscular tremors and incoordination	The clinical syndrome is reversible if affected animals are removed from ergotized pasture.
^* Pennisetum clandestinum Kikuyu grass	Grass, creeping forming a dense sward and with very inconspicuous flowers/seeds	Cultivated tropical to subtropical pasture grass	Ruminants, horses	Unidentified toxin causes upper alimentary tract distension and irritation and nephrosis (“kikuyu poisoning”) in ruminants. Calcium oxalate crystals deny calcium to horses, producing nutritional secondary hyperparathyroidism (lameness, weight loss, jaw swelling).	“Kikuyu poisoning” predisposing factors are poorly understood, but believed to be stressors such as drought and insect attack. No effective treatment is known. There is a high case fatality rate. Calcium oxalate (horses)—remove from the pasture and remineralize bones by feeding a mineral supplement with a Ca:P ratio of 2:1, 2 kg/horse/wk for 6 mo.
^* Persicaria spp Smart weeds	Herbs with soft leaves and tubular stipules clasping the stem where leaves join; spikes or pink flowers	Weeds of waterway and reservoir margins in eastern states	Ruminants	Unidentified toxin causing photosensitization	Supportive therapy for photosensitization (shade, anti-inflammatory, rehydration). No specific therapy available. Deny further access to plants.
^* Phalaris aquatica Australian phalaris, Toowoomba canary grass	Grass, clumped with a compact cylindrical seedhead	Cultivated temperate pasture grass	Ruminants	Indole alkaloids causing “phalaris staggers” with hyperexcitability, muscle tremors and paresis	No specific effective therapy is available. Prevent by dosing with slow-release cobalt preparations (cobalt bullets) before grazing.
Pimelea trichostachya , P simplex , P elongata Flaxweeds	Upright annual herbs with opposite leaves on multiple branches, each ending in a flower spike carrying numerous flask-shaped green or yellow-green flowers; hairy to different degrees depending on species	In dense populations in disturbed habitats in inland northeastern regions	Cattle	Simplexin (irritant diterpenoid) causes a unique syndrome in cattle only consisting of chronic right-sided heart failure, anemia, and persistent diarrhea. If other animal species are forced to eat the plants (a very rare occurrence), only diarrhea occurs.	Plants are very unpalatable. Ingestion normally occurs after the plants die and their fragments contaminate other pasture components. Poisoning cases are most likely after more-than-normal winter rains promote dense growth of the plants and then less-than- normal rains in the following summer allow dry plant fragments to remain on pasture. No effective treatment is known.
Polypogon monspeliensis Annual beard grass	Grass, tufted with compact cylindrical seedheads	Coastal and inland areas of subtropical and temperate regions; seasonally flooded areas	Ruminants, horses	Corynetoxins (tunicaminyluracils produced by Rathayibacter toxicus bacteria in seedhead nematode galls) cause “Stewart range syndrome” with convulsions and death in most cases	Corynetoxins—a cyclodextrin toxin binding agent is under development as an antidote. Immunization is being developed for prevention.
Portulaca oleracea Pigweed, Inland pigweed, Munyeroo	Prostrate succulent herb with thick branched brown or red stems and wedge-shaped leaves and yellow flowers	Widespread native weed of cultivation and disturbed habitats including stockyards	Ruminants	Soluble oxalates— hypocalcemia, nephrosis. Nitrates—methemoglobinemia	Most poisonings are of hungry animals with access to lush plants in stockyards. Soluble oxalates—calcium borogluconate injection (prognosis guarded). Nitrates—IV methylene blue.
Pteridium esculentum Austral bracken	Robust large fern; simple fronds with recurved margins	Coastal and subcoastal regions; native to open forests; weed of pasture	Cattle, horses	Ptaquiloside—thrombocytopenia and neutropenia resulting in widespread hemorrhage and terminal septicemia; chronic intake (>2 yr) is associated with urinary bladder neoplasia and chronic hematuria in cattle (rarely in sheep). Thiaminase—‘‘bracken staggers” (ataxia and cardiac dysfunction) in horses (rare)	Young fronds are the most toxic part of the plant. Ptaquiloside—no effective treatment is known. “Bracken staggers” of horses—IV thiamine (vitamin B₁).
^* Raphanus raphanistrum Wild radish	Herb with coarse rosette of leaves at ground level and branched flowering stems with 4-petalled white, yellow or pink flowers	Widespread weed of cultivation in temperate areas	Ruminants	S-methylcysteine sulfoxide (SMCO)—hemolysis	SMCO—No effective treatment is known.
^* Rapistrum rugosum Turnip weed	Herb with coarse rosette of leaves at ground level and branched flowering stems with 4-petalled yellow flowers	Widespread weed of cultivation	Ruminants	SMCO—hemolysis. Probably sulfur—polioencephalomalacia	SMCO—No effective treatment is known. Polioencephalomalacia—thiamine may not be effective.
Rhodomyrtus macrocarpa Finger cherry, Native loquat, Wannakai	Shrub or small tree with opposite broad leaves carrying oil glands, white 5-petalled flowers, followed by fleshy cylindrical globular to oblong red fruit	Rainforests of northeastern Queensland	Ruminants, humans	Unidentified toxin causes permanent blindness from optic nerve degeneration	Leaves and fruits have poisoned ruminants; fruits poison humans. No effective treatment is known.
^* Rumex spp Docks; ^* Acetosella vulgaris Sheep sorrel	Herbs with rosettes of broad leaves and tall branched flowering stems carrying green to red flowers and seed pods	Weeds of temperate pasture mostly in southeastern states	Ruminants	Soluble oxalates— hypocalcemia, nephrosis	Toxicity is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded).
Salsola kali Soft roly-poly	Annual upright herb with gray-green succulent leaves and dry fruits with a circular, papery wing	Widespread weed of all mainland states	Ruminants	Soluble oxalates— hypocalcemia, nephrosis	Toxicity is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded).
^* Salvia reflexa Mint weed	Erect herb with square stems and blue-green leaves with felty hairs and pale blue tubular flowers in opposite pairs along stems	Widespread weed in inland Queensland and New South Wales	Ruminants	Nitrates—methemoglobinemia	Toxicity is most likely from rapid large plant intakes. Plants contaminating hay can cause poisoning. Nitrates—IV methylene blue.
Sarcostemma brevipedicellatum Caustic vine, Caustic bush, Pencil caustic	Leafless gray-green succulent shrub or scrambling vine with small bunches of waxy white flowers and long pods with milky sap	Widespread in northern areas, both coastal and inland	Cattle, sheep	Unidentified neurotoxin, suspected to be similar to cynanchoside—collapse, clonic convulsions	No effective treatment is known.
Schoenus asperocarpus Poison sedge	Grass-like tussock of thin leaves with flower spikes extending above the leaves and bearing flowers (spikelets) in a zig-zag arrangement surrounded by broad brown square-tipped bracts	Southwestern Australia	Ruminants	Galegine—acute pulmonary edema	No effective treatment is known.
^* Senecio jacobaea Ragwort	Erect herb with finely-divided leaves and bright yellow daisy-type flowers in clusters at the top of the plant	Weed of pasture and cultivation in southern regions	Cattle, horses	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known. See Pyrrolizidine Alkaloidosis: Introduction.
Senecio linearifolius Fireweed	Erect shrub with long pointed leaves and flower heads in bunches resembling those of ragwort	Coastal and subcoastal New South Wales, Victoria, and Tasmania	Cattle, horses	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known. See Pyrrolizidine Alkaloidosis: Introduction.
Senecio lautus Fireweed, Variable groundsel	Erect herb with leaves either simple or with dissected edges and clusters of yellow daisy-type flowers	Widespread south of 20°S latitude on heavy clay soils	Cattle, horses	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known. See Pyrrolizidine Alkaloidosis: Introduction.
^* Senecio madagascariensis Fireweed	Very similar to S lautus and distinguished by 20-21 bracts under the flower head compared with 11-14 in S lautus	Naturalized in eastern coastal subtropical and temperate regions	Cattle, horses	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known. See Pyrrolizidine Alkaloidosis: Introduction.
Senecio quadridentatus Cotton fireweed	Erect herb with narrow leaves covered in cottony hair and with bunches of small slender flower heads at the top of the stems	Weed of pasture and cultivation in southeastern regions	Cattle, horses	Pyrrolizidine alkaloids—chronic hepatopathy causing mostly weight loss, irritability and compulsive walking (horses) or weight loss and persistent diarrhea with tenesmus (cattle)	No effective treatment is known. See Pyrrolizidine Alkaloidosis: Introduction.
^* Senna occidentalis Coffee senna * S obtusifolia Sickle pod	Small shrubs with compound leaves and clusters of open yellow flowers and flat long or curved seed pods	Naturalized in northern coastal and subcoastal Australia	Ruminants	Unidentified toxin causing striated muscle degeneration and necrosis with myoglobinuria	Seeds and seed pods are the most toxic. No effective treatment is known.
^* Setaria sphacelata	Grass, tall, tufted with a long compact cylindrical seedhead	Cultivated tropical pasture grass	Ruminants, horses	Soluble oxalates—hypocalcemia, nephrosis in ruminants, very rarely horses. Calcium oxalates crystals deny calcium to horses, producing nutritional secondary hyperparathyroidism (lameness, weight loss, jaw swelling).	Toxicity from soluble oxalates is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded). Calcium oxalate (horses)—remove from the pasture and remineralize bones by feeding a mineral supplement with a Ca:P ratio of 2:1, 2 kg/horses/wk for 6 mo.
^* Silybum marianum Variegated thistle	Herb with broad green and white leaves edged with small yellow spines, pink thistle-type flower heads	Weed of cultivation in southern and eastern regions	Ruminants	Nitrates—methemoglobinemia	Toxicity is most likely from rapid large plant intakes. Nitrates—IV methylene blue.
Solanum spp Nightshades, Potato weeds	Herbs to large soft-wood shrubs with star-shaped, 5-petalled white or purple flowers with prominent erect yellow staminodes centrally, followed by fleshy green, black, yellow, or red fruit	Widespread throughout all states; some as weeds of pasture or cultivation	Ruminants	Glycosidic steroidal alkaloids cause gastroenteritis with diarrhea. They are poorly absorbed, but if absorption occurs, hemolysis (hemoglobinuria), depression, and stupor may occur.	No specific effective treatment is known. Dosing with activated charcoal and rehydration appear to be rational responses.
^* Stachys arvensis Stagger weed	Erect herb up to 30 cm high with opposite round-lobed leaves on square stems and tubular pinkish flowers	Widespread weed of cultivation	Ruminants, horses	Unidentified toxin causing incoordination	Removal from access to plants will result in recovery in most cases.
Stemodia kingii	Erect herb with pale blue tubular flowers	Inland regions of Western Australia	Ruminants	Cucurbitacins—irritation of the upper GI tract and increased permeability of blood vessels producing sudden death with diarrhea	No effective treatment is known.
Stypandra glauca Blind grass	Erect perennial herb with grass-like green leaves and terminal flower heads with pendulous, 6-petalled blue flowers with 6 prominent yellow anthers	Mostly in southwestern Australia with populations in New South Wales	Ruminants, horses	Stypandrol—degeneration of retina and optic nerves and tracts causing permanent blindness	No effective treatment is known.
Swainsona spp Darling or Swainson peas	Herbs with compound leaves with many leaflets and usually large, showy pea-type flowers with blue, pink, purple, or red petals, followed by inflated seed pods	Subtropical and temperate regions in all states	Ruminants, horses	Swainsonine (an indolizidine alkaloid) produces acquired lysosomal storage of mannose leading to incoordination, nervous derangement, weight loss, infertility, abortion	Animals are reputed to develop a craving for the plants. Toxicity requires access for at least 2 wk (horses) or 4 wk (ruminants). No effective treatment is known. Less severely-affected animals will recover if access is prevented.
Terminalia oblongata oblongata Yellow wood	Deciduous tree up to 8-12 m tall with dark gray, furrowed bark, leaves simple in clusters on branches, small white flowers and fruits with a central oval seed enclosed in 2 papery wings	Confined to the McKenzie River basin of northeastern Queensland	Cattle, sheep	Hydrolyzable tannins; cattle—hepatogenous photosensitization and/or nephrosis; sheep—convulsions	Toxicity is most likely from large plant intakes. No effective treatment is known.
^* Trachyandra divaricata Branched onion weed	Herb with rosette of fleshy green linear leaves and an erect dichotomously-branched flower spike with numerous darkly-striped white flowers	Naturalized in coastal southwestern Australia; small populations also in New South Wales and South Australia	Horses, sheep	Unknown toxin causing ataxia and recumbency with degeneration of CNS tissues and intense lipofuscinosis of neurons.	No effective treatment is known.
Trachymene glaucifolia , T ochracea , T cyanantha Wild parsnips	Annual herbs with rosettes of divided leaves at ground level and upright flowering stems bearing clusters of small flowers in flat-topped bunches	Subtropical inland areas of eastern states, in grasslands or woodlands	Sheep	Unidentified teratogenic toxin causing limb deviations through interference with normal development of long bone growth plates—‘‘bent-leg” of lambs. Some association with infertility (low lambing percentages). Unidentified (cardiac?) toxin causing sudden death in sheep under stress of mustering. Unidentified toxin causing diarrhea in young sheep.	No effective treatment is known. Many lambs affected at birth will recover.
Trema tomentosa Poison peach	Small tree with alternate leaves tapered at each end with toothed margins and rough texture, very small white flowers in clusters in the leaf angles, followed by small black fruits	Coastal and inland northern and eastern Australia	Ruminants, horses	Unidentified hepatotoxin causes acute coagulation necrosis of periacinar hepatocytes with rapid death after hepatoencephalopathy in some cases.	No effective treatment is known.
Trianthema spp Red spinach, Hogweed, Black or Giant pigweed	Succulent prostrate herbs	Widespread in semiarid and arid regions of northern Australia	Ruminants	Soluble oxalates— hypocalcemia, nephrosis. Nitrates—methemoglobinemia	Toxicity is most likely from rapid large plant intakes. Soluble oxalates—calcium borogluconate injection (prognosis guarded). Nitrates—IV methylene blue.
^* Tribulus terrestris Caltrop, Puncture vine	Prostrate herb with branching stems and compound leaves with yellow 5-petalled flowers and spiny burrs	Widespread in all mainland states; weed of pasture	Sheep	Steroidal saponins cause hepatogenous photosensitization. β-carboline alkaloids cause progressive irreversible posterior ataxia.	Toxicity is most likely when the plant dominates available feed. Wilting is thought to enhance toxicity by steroidal saponins. No effective treatment is known.
^* Trifolium spp Clovers	Herbs with trifoliate leaves and tight clusters of pea-type flowers with white, yellow, or pink petals	Cultivated pasture legumes in temperate regions	Sheep	Unidentified photosensitizing toxin. Phytoestrogens— infertility	No effective treatment is known.
^* Urochloa panicoides Liverseed grass	Grass, prostrate or erect with hairy leaves and branched seedheads	Naturalized in Queensland and New South Wales	Ruminants	Nitrates—methemoglobinemia	Toxicity is most likely from rapid large plant intakes. Nitrates—IV methylene blue.
^* Verbesina encelioides Crownbeard	Erect herb with stem-clasping leaves and bright yellow daisy-type flower heads	Weed of pasture in eastern regions; prefers sandy soils	Ruminants, pigs	Galegine—acute pulmonary edema	Toxicity is most likely from rapid large plant intakes. No effective treatment is known.
^* Vicia spp Woolly-pod vetch, Popany vetch	Herbs with compound leaves ending in tendrils and pink or purple pea-type flowers	Pasture legume in subtropical and temperate regions in all states	Cattle (usually Aberdeen Angus, Friesian, and their cross-breeds), horses (rare).	Unidentified toxin can produce systemic eosinophilic granulomas in multiple organs.	Toxicity occurs when grazing dense swards of the plants. Skin lesions must be differentiated from photosensitization. No effective treatment is known.
Wedelia asperrima Yellow daisy, Sunflower daisy	Erect herb with branched stems, leaves rough to the touch, yellow daisy-type flower heads	Grasslands of northern Australia	Ruminants	Diterpenoid (kaurene) glycoside—wedeloside—causes acute coagulation necrosis of periacinar hepatocytes with rapid death after hepatoencephalopathy in some cases.	Toxicity is most likely from rapid large plant intakes. No effective treatment is known.
Wikstroemia indica Tie bush	Shrub up to 1-2 m high with red-brown bark, opposite leaves tapered at each end, greenish-yellow tubular flowers followed by red or orange fleshy fruits	Woodlands and forests of coastal eastern Australia	Cattle, deer	Irritant diterpenoid—alimentary tract irritation, diarrhea. Dicoumarin derivative—anticoagulant effect seen only in deer	No effective treatment is known.
^* Xanthium occidentale Noogoora burr	Upright herb with branches carrying broad-lobed rough leaves on stalks, clusters of oblong brown burrs covered with hooked spines	Widespread weed of cultivation and pasture	Ruminants, pigs	Diterpenoid (kaurene) glycoside—carboxyatractyloside—causes acute coagulation necrosis of periacinar hepatocytes with rapid death after hepatoencephalopathy in some cases	Only the cotyledonary (seed) leaves or burrs are toxic. Toxicity occurs commonly on river flats after rain or flooding. No effective treatment is known.
Xanthorrhoea johnsonii , X fulva Grass trees	Rosette of numerous grass-like leaves arising from a trunk (caudex) constructed of leaf bases of fallen leaves, with a tall flower spike with a long cylindrical compact mass of flowers and bracts. X fulva does not develop a caudex.	Coastal and subcoastal regions of eastern Australia	Cattle	Unidentified toxin—transient spinal cord dysfunction causing posterior ataxia and urinary incontinence	Flower spikes are the most toxic part of the plants. There may be a delay of several days between last access to the plants and onset of the syndrome. Supportive care is required. Most affected animals recover completely with symptomatic treatment.
^* Zantedeschia aethiopica Calla lily, Arum lily	Herb with dark green fleshy leaves with upright white tubular flower (spathe) with yellow stalk (spadix) in its center.	Cultivated garden plant, naturalized in coastal southern (particularly southwestern) Australia	Ruminants, horses, dogs, cats	Raphide calcium oxalate crystals—buccal irritation	Effects are likely to be transient and not require therapy unless laryngeal edema occurs.
^* Zea may Maize	Grass, erect, robust	Cultivated grain crop	Ruminants	Nitrates—methemoglobinemia. Cyanogenic glycosides—sudden death	Nitrates—IV methylene blue. Cyanogenic glycosides—IV sodium thiosulfate, 660 mg/kg plus an oral dose (30 g cattle, 5 g sheep). Repeat treatment may be needed for relapses.
Zieria arborescens Stinkwood	Shrub to tree with trifoliate leaves and bunches of small white flowers	Forests of southeastern mainland and Tasmania	Cattle	Unidentified pneumotoxin causing severe pulmonary edema and emphysema	No effective treatment is known.

^*Plants introduced to Australia (not indigenous) are indicated by an asterisk (* ) in front of the scientific name.

^†For detailed information on plant distribution, consult Australia’s Virtual Herbarium website (http://www.chah.gov.au/avh.html).

^‡Effective therapeutic regimens are not known for many acute poisonings. The use of activated charcoal as an adsorbent for organic toxins should be considered for these.

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