Toxicology Trivia for $1000 - These are in fruits of the "rose" family and in some roots that contain cyanogenic glycosides and other cyanide containing compounds. It would actually take a fair amount of work to ingest enough to reach toxicity:
Bitter almonds
Apricot kernels
Peach pits
Plum sees
Apple and pear seeds
Cassava (actually have to wash the root prior to eating - skin contains the CN)