This article contains information that relates to the non-canon game PikSpore, which was created by Neini, a user on this Wiki.
Black Nectar is sort of a backwards form of Nectar. Instead of making leaf or bud Pikmin into flower Pikmin, it reverses the process, turning them into leaf Pikmin. Certain enemies attack using this horrible goop, and sometimes it is left behind by defeated enemies like the Gulagg. Black Nectar can be destroyed by Black Pikmin, who are the only ones immune to the negative effects.
When Captains touch black nectar, it gets stuck to them, gradually sucks away their health and makes them slower. It can be removed by spinning around rapidly.