Citrus limonia Osbeck, Reise Ostindien 250. 1765 (Syn: (=) Citrus taitensis Risso; (=) Citrus volkameriana V. Ten. & Pasq.) as per GRIN;
Common names for this fruit include rangpur, named after Rangpur, Bangladesh, a city known for this and other citrus fruits. This is where the word originated in the Bengali language. The rangpur is known as a Canton lemon in South China, a hime lemon in Japan, as Limão Cravo or Limão Galego in Brazil, and mandarin-lime in the United States.
Rangpurs are highly acidic and can be used as a substitute for commercial limes. However the name lime in connection with this fruit is often misleading, because there are very few similarities between the rangpur and other fruits called limes.
(From Wikipedia on 26.3.14)
Rutaceae Week : UD8 Rangpur lime from California: Submitting a photograph of Rangpur lime… Citrus X limonia.. a hybrid between lemon and mandarin orange ..
as part of a herbal class we tasted these … very sour, not pleasant as is to directly eating it… even though the ring looks inviting…
((there is interesting story with use of beverages etc at the wikepedia : see URL: http://en.wikipedia.org/wiki/Rangpur_%28fruit%29 ))