Details are a little hazy ...
Of the two PIE roots *HebVl- and *meHlo-, the former is represented in 5 or maybe 6 branches (Celtic, Baltic, Slavic, Germanic, Italic/Oscan). The latter in, at least, Italic/Latin and Hellenic and just maybe in Hittite, where there's a bit of a mystery as to whether it means grapes, apples, or generically fruit. In all the other branches it seems to mean apple and somewhat generically fruit. Folk taxonomies are never exact, and as new species are discovered or introduced, old names get reused in interesting ways: e.g., apples of Hesperides are sometimes identified as oranges. Folktales abound involving apples, e.g., the apple of discord that starts the Trojan War.
