Pixie-cup Lichen

Tiny light green and have a concaved top like a cup. The base is a wavy, green "leaf". They're about 1/2 cm in diameter and just over 1 cm tall. As with all Lichen, these are "composite organisms consisting of a symbiotic organism composed of a fungus (the mycobiont) with a photosynthetic partner (the photobiont or phycobiont), usually either a green alga (commonly Trebouxia) or cyanobacterium (commonly Nostoc)." - Wikipedia