The Nirnroot is a rare plant with magical properties that usually grow near bodies of water and has the potential to create unique potions.
It emits a soft blue-white glow and a distinctive chiming noise. It is sometimes found underground as well, and a crimson variety exists and can be found in Blackreach.
Imperial herbalist Chivius Regelliam theorized that the Nirnroot was much more plentiful in the past, but a cataclysmic event ravaged its population, which he thought could have been the Sun’s Death of 1E 668, when the Red Mountain erupted and filled the sky with ash for a whole year.
However, the volcanic ash could have been the Nirnroot’s blessing as well as its downfall. As Discovered by Sinderion, expert researcher of Nirnroot, the volcanic ash of Vvardenfell is rich with ash salts
Combined with the fertile soil of Cyrodiil, the Nirnroot was able to survive and adapt rapidly due to its magical nature.
Unfortunately, the Nirnroot’s population is once again on the decline in the Fourth Era, and no one is certain of the reason.