The Void Plant is a crop added by Thaumic Bases. When fully grown, it drops its own seeds and Void Seeds.
Those Void Seeds are created by infusing a regular seed with a bunch of Alienis and Tenebrae. However, the seed itself looses [sic]
the ability to grow - you are overinfusing it. However, it might be possible to bring the seed back to life using the knowledge of plants you've just learned! By infusing a void seed with all kinds of plantlife [sic]
you have managed to return the ability to grow to the poor seed.