The word for "vegetarian" in Greek is "hortofagos", which literally translates to "weed eater". Yes, very funny, but I kid you not.
Dandelion Green = Pikralida Peekrahleethah πικραλίδα
Amaranth Greens (Green / Red / Slender) = Vlita Vleetah βλήτα
Chicory = Radikia Rahtheekeeah ραδίκια
Chard / Swiss Chard = Seskoula Seskoolah σέσκουλα
Wild Sorrel = Agria Oxalida Ahgreeah Oksahleetha άγρια οξαλίδα
Curly Endive (Used a lot in fricassee) = Andithia Andytheeah αντίδια
Radish Greens (Radishes) = Rapanakia Rahpahnahkeeah ραπανάκια
Spinach = Spanaki Spahnahkee σπανάκι
Beet Greens (beetroot) = Padzaria Padzahreeah παντζάρια and onion, leeks and garlic.
topped with lemon and olive oil.
Encyclopedia of medicinal plants by Andrew Chevalier
And if they don't want to live on the prairie and eat chard and radish greens, they can get serious about joining modern civilization and making a contribution.