From time to time, I correspond with others in my craft--herbalists or eccentrics who study rare plants and local oddities. We trade discoveries, and sometimes warnings of what lies ahead.
One alchemist in the Wetlands wrote of an excavation team her husband was part of, uncovering signs of a long-lost primordial grass... but she never sent word of its abundance or accessibility.
If you can, check on Caitlin Grassman in Menethil Harbor.