Yerba Mate is very much an acquired taste. The South American plant is extremely popular in Brazil and Argentina, where its drank throughout the day and as a social gathering (similar to getting together for coffee in the US). The mate is typically put loose into a cup and sipped through a special filter straw called a bombilla, but you can also steep it as you would any other tea. It's a strong, bitter, earthy flavor that takes some getting used to, but once you do, you can come to love this traditional energizing drink.
Yerba mate is a unique herbal tea from South America that's not made from the traditional tea plant, Camellia sinensis. It's its own plant, and when dried and ground up it makes a delicious, slightly bitter, sipping tea that's popular particularly in Argentina.
It packs an energetic punch, but it doesn't give you the same peak and crash as traditional caffeine. You can steep it like normal tea, or get fancy and get a traditional gourd and bombilla to sip it like a South American local.