Aconite

Aconite (H) Known location: near Fort Hold Growth form: root Uses medicinal herb, anodyne, for heart palpitations. Root is used in a powdered form. Outside Info: All parts of this plant are toxic. The root is used externally for nerve- related pain. It is a sedative, painkiller, and anti-fever treatment. The plant grows to 1.5m with helmet-shaped violet flowers in early summer.

[Wikipedia

Key:

H=this plant is listed only in a historic manner, and may or may not currently exist on Pern. It can probably be safely assumed it still exists somewhere.

I=This plant is a known import to Pern from Earth

N=This plant is a known native to Pern

?=I was uncertain of the information and made an educated guess