Caladium is a popular genus of plants in Nova Scotia, grown for their decorative variegated leaves.
Like other arums, caladium contains oxalate crystals. If eaten, the leaves may cause burning, swelling, and choking. Fortunately, handling the plant is probably safe, although gloves might be useful if transplanting numbers of individual plants from the garden to pots for overwintering.
The greatest concentration of the toxin occurs in the leaves.
Calcium oxalate, a compound derived from oxalic acid, as well as enzymes that trigger the release of histamine in the bloodstream of persons who ingest the leaves. Oxalates are needle-like crystals, which, when eaten, may pierce the mouth, throat, and digestive tract as they pass through, causing, at the very least, intense discomfort.
TYPICAL POISONING SCENARIO
The main problem lies with infants, toddlers, or pets who, once attracted to the showy flowers and foliage, may nibble on the leaves. If arums are kept out of curious mouths, there is little further risk, as they are quite safe to handle.
Even small doses of oxalate toxin is enough to cause intense sensations of burning in the mouth and throat, swelling, and choking.
In larger doses, oxalate causes severe digestive upset, breathing difficulties, and—if enough is consumed—convulsions, coma, and death. Recovery from severe oxalate poisoning is possible, but permanent liver and kidney damage may have occurred.
CALADIUM POISON INFORMATION
Oxalates are unstable salts of oxalic acid. When eaten, they break down to release the highly poisonous acid.
The sour flavour of sorrel (Rumex species), wood sorrel (Oxalis), and even rhubarb is due to the presence of the acid.
Some plants may contain differing amounts of potassium or calcium salts, rendering them unsafe, particularly in the buckwheat and goosefoot families.