...Harry found himself shunted aside by a witch with a satsuma jammed up her left nostril.
- St Mungo's reception area at Christmastime (OP23)
"Mphf?" said Mr. Weasley, whose head had been nodding over the satsuma he was peeling (HBP16)
A variety of tangerine with a sharp taste, originally from Japan (NSOED).
Satsumas are traditionally eaten at Christmastime in the U.K.