Iranian blackberry is an aggregate fruit that is composed of many smaller fruits called drupes. Which city or province grow: North of Iran. Harvest Season: Summer. Green raisins B-berry plants The fruit is very dark purple with smooth, fragile skin. In the middle of the cluster is a greenish-white core that extends to almost the bottom of the berry. Blackberries can be easily confused with raspberries, but raspberries (including black...