ptisan (TIZ-uhn, ti-ZAN) - n., a medicinal infusion, originally made from barley soaked in water; herbal tea.
In the last sense, this is exactly an alternative spelling of tisane. The first is the original tisane -- in Middle English it meant pealed barley as well as barley water, from Old French, from Latin ptisana/tisana, from Greek ptisánē, from ptissein, to peel/crush. Here's a modern Korean barley tea:

Thanks, WikiMedia!
---L.
In the last sense, this is exactly an alternative spelling of tisane. The first is the original tisane -- in Middle English it meant pealed barley as well as barley water, from Old French, from Latin ptisana/tisana, from Greek ptisánē, from ptissein, to peel/crush. Here's a modern Korean barley tea:

Thanks, WikiMedia!
---L.