The Black Flowers of Darthin

In the dead lands of Darthin, the flora of the land is often spare and sickly. The necromantic energies that are prevalent in the land on the shifting winds. Often draining and stunting the growth of flora and fauna.
But those brave enough to travel those lands have found one species of flora not just growing but thriving. Among the ruins of the cities that lay among dotted the area among the sparse vegetation and dead trees. If one is lucky enough to come across a growth of Nigreos Vita, also commonly known as the Black Flowers of Darthin. These growths are coveted by druids that work in the land seeking to undo the destruction there. Taking years to grow and thrive in the area, the plants have a peculiar effect of not withering when exposed to necromantic energies , but thriving in it. Clusters of the large black and purple flowers , grow where the necromantic winds pass through and as they do the lessen the effect of the energies.
Making them key in restoring the area some druids claim, but this property also makes them coveted by treasure hunters and apothecaries meaning they fetch a high price. Leading to them being cut and removed as soon as they are found inhibiting their ability to heal the land.
When mixed  with the proper reagents the flower has one of two effects, they can either lead to the rapid absorption of necromantic energies that can be used to cleanse those affected by necromantic diseases. Used on afflicted areas it acts as the some some holy waters and oils of divine deities will dispearcing energies and making undead shy away from where they were spread.  
The other effect the agents have is rare but documented among healers, is that in some people the mixture of the flower gives divine visions to those. Showing the calamity of some past or possibly future event, often leaving those mad for days after with ramblings.
Often all saying the same thing in a semi comatose state "The Prince Seeks to find us."