Strangers in a mate circle don't get their own cup — the same gourd and metal straw are refilled and passed hand to hand, everyone drinking from the identical bombilla.
Mate is a bitter, grassy infusion made from dried yerba mate leaves steeped in hot water inside a hollow gourd and sipped through a metal straw called a bombilla. Argentines carry a thermos of hot water and a mate gourd everywhere — parks, sidewalks, offices, bus stations — refilling and passing it within a circle of friends.