Looking up the English translation of 晩白柚 (banpeiyu), I came up with “Citrus maxima” and “Citrus grandis.” I suppose either would do if viewed from the outside, but once peeled, it’s no bigger than a grapefruit. A farmer in Yatsushiro came up with a 5.4-kilogram (about 12 pounds) maximus Citrus maxima. Without the rind, though, it’s probably a pound. - William