POISONOUS PARTS
Whole plant, especially the tubers.3,4
TOXICITY
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Toxic Constituents
Calcium oxalate raphides and other unidentified toxins.3–5
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Toxic Dose
Small amount of sap can cause local symptoms.5,6
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Mechanism
The toxic mechanism of the poisonous plants in the Araceae family is not fully understood. Calcium oxalate raphides stored in specialized cells known as idioblasts are released when subjected to mechanical pressure such as ingestion and contact, causing tissue irritation and inflammation. Other toxic ingredients that are commonly found in the family, such as sapotoxins and cyanogenic glycosides, may also play a role.4,6
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Poisoning Features
Skin contact: contact dermatitis. Eye contact: conjunctivitis. Ingestion: severe pain, burning sensation and inflammation of the oral cavity, tongue, throat and oesophagus; it can also cause salivation, vomiting, diarrhoea and dysphagia.3–5,7
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Poisoning Events
The New Zealand National Poisons Centre recorded 556 enquiries of acute exposure to the plant during 2003–2010, mostly involving children. In Italy, a woman contacted the sap while trimming the plant. Swelling, redness and itchiness of her hands appeared 2–3 hours after exposure.5,6
CLINICAL MANAGEMENT
Supportive treatment. Maintenance of airway by intubation or tracheostomy may be required for severe cases with airway compromise.3,7
IDENTIFICATION FEATURES
Perennial herbs, with rhizomes. Leaves radical; petioles 0.4–1(–1.5) m long, sheathing below; leaf blades 15–45 × 10–25 cm, thickened. Peduncles 40–50 cm long. Spathes 10–25 cm long, limb white. Spadix 6–9 cm × 4–7 mm, yellow. Berries 10–12 mm in diameter, pale yellow. Seeds about 3 mm in diameter, obovate-globose.8
LABORATORY ANALYSIS
Calcium oxalate raphides can be detected by polarizing microscopy.9
