I came across the Silphium plant that went extinct around 64 AD. It is believe that emperor Nero was to have eaten the last known stalk!
It surprised me that such a valuable plant was not cultivated through agriculture.
Are there other plants that we know to have literally eaten out of existence?
That’s a good lead. Could you point me to some source or information? I can look it up / read more.
You could start by reading New Lives for Ancient and Extinct Crops. I recommend the other books by Paul E. Minnis, like Famine Foods. These books are academic, though - so don’t expect a fun and accessible science journalism read.