Yellow (mountain) saxifrage

At the edge of the clear waters of the brook, a flowerbed of yellow stars catches the eye. When young, the flowers are male and only have 10 stamen and a large shiny disc full of nectar. Later, when the stamen have fallen off, they become female and two small nipples appear on the nectar disc, ready to welcome pollen from a younger neighbour. The small rare and protected apollo butterfly has chosen this plant to protect its eggs and feed its caterpillars.