Silverthorn is an Elven plant with lethal properties.
Silverthorn (aelebera by the elves, Elleberry through corruption by humans, also Sparkle Thorn) is a shrub that grows on the edge of Moraelin, the Black Lake, in the Great Northern Mountains. The plant is made of light silver-green leaf of three lobes, red berries like holly berries, and branches covered in silvery thorns similar to that of rose branches. Also Silverthorn requires a constant water source, which is why it is found on the edge of lakes. However, in the case of the Silverthorn that grew on the edge of Moraelin, the lake's water level had risen to the point where the plant was completely submerged.
Silverthorn in its base form is not poisonous or lethal. To boost the magical properties of the plant, a speical distillation process is needed as well as an arcane ritual. The distillation process and arcane ritual are beyond the ability of most of the inhabitants of Midkemia except for a few. When properly made, the poison brew will cause the target to sleep unto death. However, the same poison that has the power to kill can also cure.
In the lore of the elves of Elvandar, there was a Prince of Elvandar who was betrothed to a woman who had caught the eye of a moredhel warrior. This moredhel was rejected by her, in his wrath the moredhel poisoned her with the draught brewed from the plant. The Prince learns of this act and begins what is known as the "Hopeless Quest," to find more aelebera (Silverthorn) to cure her. But the Silverthorn only grows in Moraelin, a place sacred to the moredhel and where no elf may set foot upon. Thus the Prince of Elvandar walked the edge of Moraelin until a canyon was created around it, called the Tracks of the Hopeless. For he may not enter Moralein, nor will leave until he has found which will save his beloved. Legend says that he still walks there still.
The poison brewed from this plant is used in attempt on Prince Arutha's life during his wedding to Princess Anita. The assassin, Laughing Jack, is foiled by James (Jimmy) and the bolt strikes Anita, instead of Arutha. The magician Pug is able to slow the progression of the poison by putting Anita in a state of magical suspended animation until a cure can be found. Arutha, James, and others take up a quest to discover the mysterious origins of Silverthorn.