Wrathful fruit borrowed by Steinbeck from the Battle Hymn of the Republic?
I believe the answer is:
grapes
(Other definitions for grapes that I've seen before include "Fruit that grows in clusters" , "John Steinbeck wrote 'The . . . . . . of Wrath'" , "Green or purplish-black juicy clusters" , "Fruit for wine" , "They grow on vines" .)