Castor beans, Rhubarb leaves, parts of cherry and peach trees, the list goes on. Here are some: http://plantanswers.tamu.edu/publications/poison/poison.html
Thank You for your son’s service to our country.
I am sorry for your great loss.
a poisonous houseplant if ingested by your chewing kitty is philodendron////spiderplants aren’t poisonous tho to cats