Anacardium occidentale (Cashew Nut)

The shell surrounding the green cashew nut kernel contains a very acrid and irritant oil. The nut itself contains poisonous oils which need to be evaporated through roasting before the nut can safely be eaten. 

Cotinus coggygria (Smoke Tree)

The sap evidently causes a skin reaction (dermatitis). 

Mangifera indica (Mango)

The leaves and sap can cause skin problems (dermatitis). Eating too much mango can evidently cause kidney inflammation.

Rhus radicans (Poison Ivy)

Contact with the sap of Poison Ivy causes a severe skin reaction (dermatitis) in susceptible people and the reaction can persist for days. Leaves and fruit contain a poisonous resin and eating them causes an upset stomach and can even cause death. 

Rhus succedanea (Japanese Wax Tree, Scarlet Rhus, Sumac)

Contains a resin that causes a severe skin reaction (dermatitis) in susceptible people.

Schinus molle (Pepper Tree)

Fruit are used for producing red pepper but can be toxic if eaten in quantity. 

Schinus terebinthifolius (Japanese or Brazilian Pepper Tree)

Fruit can be toxic if eaten in quantity. 

Smodingium argutum (African Poison Ivy)

The sap contains a resin which causes a severe allergic reaction when it comes into contact with a susceptible person's skin. The reaction can include swelling, itching, rash, blisters and pain, which can persist for days after contact.