Lily of the valley
A symbol of purity, joy, love, sincerity, happiness and luck, lily of the valley has much significance beyond the United Kingdom. It's actually the national flower of Finland, and in France, on 1st May for La Fête du Muguet, lily of the valleys are gifted to loved ones
Lily of the valley poisoning occurs from ingestion of the leaves, flowers, or roots. The cardiac glycosides are gastrointestinal irritants, may be responsible for a variety of cardiac arrhythmias (e.g., irregular pulse, bradycardia, rapid thready pulse, ventricular fibrillation), and can be fatal.