By JANE PERLEZ BUDAPEST, Hungary — The Hungarian rapper known as Joci Pápai was on his way to a concert in the southern Hungarian town of Szeged when he got a call from a man who said he was a member of the Hungarian government.

Rhubarb is a plant that has been cultivated for centuries, but it wasn’t until the 19th century that it became popular in Germany. The plant was initially brought to Europe from China, and it was used primarily for medicinal purposes.