Pixie Cup Lichen (Cladonia Pyxidata) is shaped like miniature golf tees. The sprinkling of light-grey-green pixie dust between them is part of the lichen. They have a light grey to pinkish hue and a rough appearance. This makes them look like they are covered with sand.
A lichen is composed of algae and fungus in a symbiotic relationship. Both plants gain benefit and neither is harmed by the relationship. The Pixie Cup Lichen looks like the name implies, a tiny cup on the forest floor, they look like they could be used by the wood fairies to drink from.
If you look closely at a Pixie Cup Lichen you would that the cup is where the spores reside, these are fungal hyphae entwined about a colony of algal cells. When a raindrop lands in the cup, they are scattered about. The next generation of Pixie Cups will not grow until the soredia connect with the host algae, Pleurococcus which is a genus of green algae in the family Chaetophoraceae. The function of the algae in the process is to provide the food for the lichen, this is done through photosynthesis. The fungus is responsible for providing the structure of the lichen. Neither plant would live as well individually as they do in combination.