These small woodland plants are early risers that often peek up from under a light snow cover.
Winter aconites have cup-shaped, upward-facing, bright yellow, buttercup like flowers on stalks up to 10 cm tall. There are six petals in each flower and numerous stamens and pistils in the center. Each flower is subtended by a collar of leaf-like bracts.
The flowers are sensitive to warmth. They will remain tightly shut on cold days and only open if the temperature reaches roughly 10°C. Then they can be sure that early bees and pollinators are foraging. Winter aconites need to be pollinated because they spread by seed.
The photo was taken two days ago in the Botanical Garden of the University of Basel.