I think the ingredient Silphium described in this dish (Now considered extinct) could be Sea Holly (Eryngium spp). Its highly debated as many authors think it is some extinct variety of fennel, but from the images on the coins it doesnt look like a Fennel.
I believe there are more descriptions of it other than rough depictions on coins
Or Ferula drudeana https://en.wikipedia.org/wiki/Ferula_drudeana