Peltigera cinnamomea

Peltigera cinnamomea
Upper thallus surface of Peltigera cinnamomea contrasted with lower surface (upper left)
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Peltigerales
Family:	Peltigeraceae
Genus:	Peltigera
Species:	P. cinnamomea
Binomial name
Peltigera cinnamomea Goward (1995)
Holotype: Clearwater River Basin, Canada[1]

Peltigera cinnamomea, commonly known as the cinnamon-pelt lichen, is a muscicolous (moss-dwelling), leafy lichen in the family Peltigeraceae. The Canadian lichenologist Trevor Goward formally described the species in 1995. The lichen is found in northwestern North America's forested regions, particularly in the unique montane and subalpine forest communities of the northern Rocky Mountains. Peltigera cinnamomea grows under prolonged snow cover, surviving well into spring. This trait distinguishes it from many other Peltigera species in similar North American forest ecosystems.

Peltigera cinnamomea forms a specialised symbiotic relationship with specific strains of the cyanobacterium Nostoc, enabling it to fix atmospheric nitrogen, crucial for survival in nutrient-poor environments. This lichen is part of the broadly defined species complex centred around the widely distributed Peltigera canina. Within this complex, P. cinnamomea falls under the CICADE group, indicating a preference for moist, woodland habitats.

Characterised by its leafy thallus, which is loosely attached to its substrate, P. cinnamomea typically measures 10–30 cm (4–12 in) in diameter. The thallus has a distinctive appearance, with a dull, billowed upper surface covered in a soft, dense growth of hairs. The species name cinnamomea is reflected in the pale tan undersurface of the thallus, featuring rusty-brown, cinnamon-coloured veins. The lichen produces apothecia (fruiting bodies) that bear clear ascospores with three internal partitions.