So there are a lot of fun names for aconitum flower! In addition to wolfsbane, you can call it leopard's bane, woman's bane, mousebane (!!!!!!!) and the queen of all poisons. As one of our commenters pointed out last week, real aconitum flower is crazy poisonous, and Jekyll probably shouldn't be holding it so close to his face*. But rogue scientists are not known for their stellar safety practices, as is evidenced by Jasper's near-amputation by plant.
In real life, aconitum flower was a popular poison that--presumably--could be used to drive away werewolves. In the TGS universe, wolfsbane potion calls for only a very small amount of the plant's essence, as raw wolfsbane could easily kill just about anyone, especially Jasper. However, Jasper's earlier wolfsbane poisoning was not due to an excess of aconitum (even a tiny amount was tough to get his hands on) but rather . . . well, you'll find out why in a few pages.
*At last! a legitimate reason for a character to wear steampunk goggles!