Lunularia cruciata

Gemmae cups contain gemmae. Gemmae are dispersed when a rain drop splashes into the gemmae cup and splash out the gemmae.  The gemmae are asexual propagules that will germinate into a new thallus.

The lunar shape of gemmae cups are unique to Lunularia cruciata and the genus name refers to this shape.

The structures inside the air chamber are chlorophyllose cells, and act in photosynthesis.  Carbon dioxide is able to enter the chamber via the pores, however the pores can not close and water loss can not be prevented.