Jamboo vs. jamoon

[Alan Entwistle]

Dominik points to a confusion between two different fruits, a confusion 
that is addressed in Hobson-Jobson s.v. jamboo (cf. jamoon), where it is 
said that they are "very different fruits, though both classed by 
Linnaeus under the genus Eugenia."
	I remember the jamoon as a tart fruit found on tall trees for a 
short period in the rainy season; deep purple skin, flesh, and juice, in 
size, shape, and texture somewhere between a plum and a large olive.
	Not having travelled much in India beyond the Hindi belt, I have 
only come across what I understood to be a rose-apple (jamboo) in Bali: a 
small fig/pear-shaped, guava-like fruit with a pink blush.
	Why have these two been confused, and for how long? (see CDIAL 
s.v. jambu- and jambula-.