Black Iris is an ingredient used to make Totems at Zecora's Hut in the Everfree Forest and was added in the Everfree Forest update. The shape is a dark purple flower which it can create a rare totems, such as the friendship totem or the greater friendship totem.
Up to 5 may be held at any given time. They can be bought directly at Zecora's Hut for 5 if there is not enough for your mixture.
Black iris is primarily used for creating bigger totems, most notably being the totem of friendship & greater totem of friendship. The only standard totem made with this ingredient is the magic totem. It can take 8 hrs for this ingredient to grow.