Shimmerleaf Anaesthesia

There is a new form of pain treatment recently discovered by a healer near Grimar named Neric Harm. He studied a curious plant from the southern shores names Shimmerleaf. Making numerous experiments with different parts of the plant on animals, he discovered the leaves became poisonous after being mixed with a certain pollen from a different plant existing in the same area, leading to respiratory failure after being fed to rabbits. Touching the leaves, he experienced a profound numbness in his fingers, subsiding after a few hours.
He repeated the experiment on himself, exposing different parts of his skin to the wet, pre-treated leaves. The result was always the same, a deep anaesthesia of the treated area. Sharing his results with a local surgeon they began human experiments, treating the wounds of patients with the leaves, making a painless treatment possible. The big downside was the availability of Shimmerleaf and the pollen. Shimmerleaf is an uncommon plant and the pollen a strictly seasonal product not readily available. Luckily the pre-treatment worked on the dried leaves as well, even if the effect was not as profound as with a living plant.
After treating some patients, the downsides became visible. In some rare cases the numbness would not subside for a long time or, in rare cases, stay. Sometimes a tickling or burning sensation remained being most irritating. If the leaves came in contact with open wounds even more severe effects like difficulty with breathing or severe lasting headaches could be seen.
But considering everything, it makes the treatment of wounds and other surgical procedures much more endurable or even possible. The shimmerleaf anaesthesia is an expansive treatment due to the difficulties of producing and the rarity of the raw products.
Harm theorized that a certain kind of communication is taking place between the different plants, to what end he formulated no idea.