Blue tea from Thailand or Clitoria trifoliate (Thai name - anchan).  Also called Butterfly pea "Butterfly pea".  It is a medicinal plant and is used in Ayurvedic medicine as a sedative, anti-depressant and anti-stress remedy to improve memory.  In Thailand, it is believed that clitoris flower tea enhances immunity, improves eyesight, and has a beneficial effect on skin and hair.  Brewed Thai blue tea (anchan) gives a beautiful infusion of bright blue color.  The aroma of the drink is quite specific, with notes of corn and green peas.  It goes well with lemon, honey, lavender or rose, as well as with mint or thyme.