Monkshood (Aconitum napellus) flowers, Iceland. Monkshood, or wolfsbane, is named after the shape of its flowers. It is a popular garden and hedging plant in Iceland. However, it is very poisonous, fatal, in fact, and even touching it can cause health problems. The active toxins are a cardiac poison. This specimen was growing on common land by a housing area on the edge of Reykjavik. The flowers grow in a tall inflorescence and are normally dark purple/blue but other colours have been cultivated.