Surf and Turf

A sea potato and a land potato.

I wonder if the French would say une pomme de mere et une pomme de terre?

The sea potato is, of course, not a real potato at all but a burrowing sea urchin that goes by the name of Echinocardium cordatum.

The land potato, on the other hand, is definitely a potato, a species of perennial nightshade known formally as Solanum tuberosum.