From silphium wiki: "Theophrastus wrote in Enquiry into Plants that the type of Ferula specifically referred to as "silphium" was odd in that it could not be cultivated."
Ah gotcha, that's quite amusing. I wouldn't have submitted it if I'd had that context, this is my first time paying attention to the Silphium news cycle, but so it goes.
Several people have stumbled upon Ferula Drudeana in Turkey and remarked upon the similarities.
It was a plant that could not be cultivated with ancient methods.
This is the third independent discovery I can remember in the last decade.