Bitterbright

This glowing nettle is known both for its healing properties and its song.
The plant Bitterbright grows mainly in the region around Lake Tamsa. It is most commonly found on the edges of the swamplands where the rivers meet the lake. It is a large spiny thistle, standing about 5' at full height. It has thick, interconnected roots that grow quickly. As such, it can choke out other plants within an area. This is not necessarily a cause for alarm, as this plant has a three year life cycle. It tends to grow up quickly, forming large, glowing fields for a single season. After this, it dies back, enriching the soil and inviting other plants to grow where it once lived. It lies dormant for another two years, allowing other plants to feed off their rich nutrients, before returning in the third year.
Bitterbright has powerful healing qualities, but they are not well understood. Research on Bitterbright is limited, however, as harvesting is difficult and harvesting responsibly is even more complex. Additionally, Bitterbright has a foul taste, which some compare to lemons and old shit. This makes less potent healing potions more appealing.
Another aspect that may be hindering Bitterbright from reaching its full potential is the fact that its potency tends to increase or decrease depending on what or who it is used for. For example, it tends to be far more potent when used by rangers or druids, with the exception of druids who have a myconid focus. Druids in Gabiya have recently begun to research how Bitterbright may improve outcomes for struggling crops. This research appears promising.
Bitterbright is poisonous to humanoids without proper treatment. Proper treatment includes boiling for several hours. This, unfortunately, produces a distinctly fecal smell which many find they cannot tolerate. Elixirs made with Bitterbright tend to look beuatiful (they have a lovely purple glow), but taste awful. Experiments are currently being done with a powdered version encased in a capsule. This seems more promising.
The song of the Bitterbright can be heard at dusk and dawn during the Bitterbright's growing season. It sounds like a low murmur of several happy voices. The song itself is said to have therapeutic effects, although this has not been researched to any great extent.