Silvervine Candy is a type of lollipop confectionery which is constantly being consumed by Kokonoe throughout the BlazBlue series. The confectionery itself is said to drastically heighten the intelligence of its consumer.
The first time that Silvervine is acknowledged in the series is in Taokaka’s 'Help Me, Professor Kokonoe!' section. In this, Taokaka notices Kokonoe’s Silvervine in her hand and requests some, to which Kokonoe complies; there are unusual side effects as Taokaka begins to act far more sophisticated and intelligent when in comparison to how she normally acts. After a brief discussion about breasts and Kokonoe’s concern for Taokaka 'acting out of character', Taokaka’s head begins to let out smoke and she returns to normal. After leaving, Kokonoe decided that the candy had detrimental effects on members of the Kaka tribe and decides to destroy it; however, this event, like all in the 'Help Me, Professor Kokonoe!' sections, is non-canon.
In the real world, Silvervine (Actinidia Polygama) is a plant which effects cats in a way reminiscent of catnip (though supposedly more intensely). It is found in the mountainous regions of Japan and China and is a popular cat treat in Asia.