Thelidium amylaceum A. Massal.

Lichenised. Poorly known taxon.
Substrate: calciferous rocks
Altitudinal distribution:
Note: a species sometimes synonymised with Th. decipiens, characterised by a farinose, whitish thallus with a violet to lilac tinge, and minute, bottle-shaped, entirely immersed ascomata which are only visible by the umbilicate ostioles. The type material urgently needs further study, because this is the type species of the genus.
Switzerland: Valais; Italy: Veneto;