Lemon

A lemon was a sour citrus fruit native to Earth.

Jean-Luc Picard offered Simon Tarses lemon for his tea, but he declined. Admiral Norah Satie drank her tea with lemon. 

In 2370, Benjamin Sisko requested a Chiraltan tea with a double twist of lemon. 

Lemons are also used to make lemonade. 

In 2366, Captain Picard hoped the Barzan wormhole wouldn't turn out as the "proverbial lemon". 

Citroen