Helleborus foetidus
Common names: stinking hellebore, dungwort
Helleborus foetidus' green flowers and bruised foliage have a pungent smell, hence the common name. Their nectar contains large amounts of yeast. As the yeast consumes sugars in the nectar, this metabolic activity can increase the ambient temperature around the flowers by as much as 2°C, which attracts pollinators.
Stinking hellebores are evergreen, their foliage is finely divided, and their smallish flowers are sometimes edged in purply-red. Stinking hellebores seed themselves quite easily, but the area's gardener says they seem quite fussy about moisture and often don't flower when they land in other parts of the Garden. The Woodland Garden, for example, has a number of stinking hellebores, but they are small and none have flowered.
Photos in Garden taken mid-Feb. 2025. Flower schematic public domain. Flower close-up photo by Radio Tonwig, via Wikimedia.