Bethesda's two RPG franchises, The Elder Scrolls and Fallout, share a lot in common.
For example, they are both primarily played in the first person. They each feature massive worlds to explore, filled with fantastic creatures. Some of their gameplay elements are similar as well, such as crafting and fighting with melee weapons. However, there is one Easter egg in Fallout 4 that hints the two franchises may be even more closely related than we thought.
It all revolves around one little plant. In Fallout 4, players can find the plant on the Brotherhood of Steel airship Prydwen, where a Brotherhood of Steel scribe has been conducting research on the "experimental plant." Turns out the plant glows, is only found by water and has been found to have healing properties.
That might sound familiar to players who have spent more than few hours playing Skyrim, if the appearance of the plant didn't already give it away. The mysterious experimental plant referred to as Glowleaf in Fallout 4 is none other than Nirnroot, the healing plant found in the world of the Elder Scrolls. The fact that the scribe's entries about the plant are labeled under "NRT" (which can very easily be shorthand for Nirnroot) seems to seal the deal.
So, what does this mean? In all likelihood, not much. It's likely just a fun Easter egg Bethesda decided to throw in for fans of its other game series. If we take this Easter egg seriously, however, it means the worlds of Fallout and Elder Scrolls are somehow connected. If given thousands of years, might the world of Fallout transform into that of Tamriel? Is there some magic portal that connects the two planets? Did aliens bring Nirnroot from Skyrim and plant it on Earth for their own nefarious purposes?
We may never know the truth. Maybe someday, Bethesda will shed some light on just what it is they meant by including the plant in Fallout 4. In the meantime, it's best to steal all the Nirnroot you can find. They might just come in handy down the line.