Yerba Mate (Spanish name) is a herb tea and I drink myself so I know which tea you are talking about.
Yerba Mate (family Aquifoliaceae) is native to subtropical South America in northeastern Argentina, Bolivia, Uruguay, Paraguay and southern Brazil.
Mate is served with a metal straw from a shared hollow calabash gourd. The straw is called a bombilla in some Latin American countries.
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Here is the picture of the Two mate gourds with bombilla.