- "The green vegetable stuff was identified as cowbane. The poisonous substance it contains is an unsaturated higher alcohol, cicutoxin"
- ―DCI Wilkes to Agatha
Cowbane is an extremely poisonous plant found in several marshy areas around the British Isles, including the West Midlands. The plant is rather innocuous-looking, with a ridged stem and flower heads composed of groups of small white flowers.
Jo Cummings-Browne had used cowbane in her flower arrangements and therefore knew of its deadly properties. She later baked cowbane into a spinach quiche in an attempt to kill her husband, Andy Cummings-Browne. (The Quiche of Death)