Calicium is a genus of leprose lichens.[1]: 234 It is in the family Caliciaceae.
The sexual reproduction structures are a mass of loose ascospores that are enclosed by a cup shaped exciple sitting on top of a tiny stalk, having the appearance of a dressmaker's pin (called a mazaedium), hence the common name pin lichen.[1]: 15 They are also commonly called stubble lichens.[1]: 234
They have been used as indicator species for old growth redwood forests.[1]: 234
The discovery of a Calicium-like fossil in Baltic amber dating back 55–35 myr indicates that the main distinguishing characteristics of this genus have persisted for at least tens of millions of years.[2] A fossil-calibrated phylogeny that includes this fossil suggests that the family Caliciaceae diversified from its most recent common ancestor 103–156 Myr ago in the early Cretaceous.[3]
As of December 2020, Species Fungorum accepts 36 species in Calicium:[4]
Calicium is a genus of leprose lichens.: 234 It is in the family Caliciaceae.
The sexual reproduction structures are a mass of loose ascospores that are enclosed by a cup shaped exciple sitting on top of a tiny stalk, having the appearance of a dressmaker's pin (called a mazaedium), hence the common name pin lichen.: 15 They are also commonly called stubble lichens.: 234
They have been used as indicator species for old growth redwood forests.: 234
