Homeowners must be careful when placing plants in their garden. While palm trees provide a tropical feel to any yard, certain types of palm trees and their seeds are toxic to humans and animals.

...
Certain types of palm tree seeds are toxic.

Non-Toxic

Many different species of palm trees exist, most of which are not toxic. The yellow palm, reed palm, cane palm, bamboo palm, parlor palm and dwarf palm are non-toxic if the leaves or seeds are ingested by animals or humans, notes the American Society for the Prevention of Cruelty to Animals.

Toxic

The sago palm is perhaps one of the most toxic palm trees. Ingesting the leaves or seeds of the sago palm can cause symptoms of plant poisoning in dogs, cats and horses. Sago palm seeds are toxic to humans, as well, according to Clemson University. All parts of the betel nut palm are considered toxic to humans and animals.

Effects

Ingesting seeds from the sago palm or betel nut palm may cause severe symptoms within 12 hours. Symptoms include vomiting, diarrhea, weakness, seizures, depression, liver failure or jaundice. The seeds contain high levels of the toxin cycasin, which ultimately causes liver failure.

Prevention/Solution

Humans or animals that are thought to have ingested palm tree seeds of any type should be evaluated by a doctor or veterinarian, even if symptoms are not yet present. Very small amounts of seeds or leaves are required to produce severe symptoms, which may lead to permanent organ damage or death. Take a sample of the palm tree to the doctor or veterinarian for proper plant identification.