Quick, Amanda. Arcane Society novel.

Originally published: G.P. Putnam's Sons, 2009

Plagued by rumors that she poisoned her fiancé, Lucinda Bromley manages to live on the fringes of polite society. She tends her beloved plants and occasionally consults on a murder investigation, for the notorious botanist can detect almost any type of poison. But the murder of a lord has Lucinda shaken. She has detected a poison containing a very rare species of fern. So rare that the only specimen in England was in her conservatory - until it was stolen last month