The edge of the stream is blanketed by a magnificent carpet of yellow flowers which are called the yellow mountain saxifrage, or Saxifraga aizoides. Look closely at these beautiful little yellow stars. The plant is also particular for hosting an extraordinary guest: the small Apollo (Parnassius phœbus). This small butterfly, white with two red eyespots, is protected. It only lays its eggs on these saxifrages. The fleshy leaves will then serve as a meal for the butterfly caterpillars.