Punctelia hypoleucites

Punctelia hypoleucites
Growing on the bark of Arizona cypress in Chiricahua National Monument, Arizona. A cluster of apothecia is visible in the center of the thallus
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Lecanoromycetes
Order:	Lecanorales
Family:	Parmeliaceae
Genus:	Punctelia
Species:	P. hypoleucites
Binomial name
Punctelia hypoleucites (Nyl.) Krog (1982)
Synonyms
Parmelia hypoleucites Nyl. (1858) Parmelia borreri subsp. hypoleucites (Nyl.) Nyl. (1860)

Punctelia hypoleucites, commonly known as the southwestern speckled shield lichen, is a species of foliose (leafy) lichen in the family Parmeliaceae. First formally described by Finnish botanist William Nylander as a species of Parmelia, it was transferred to the genus Punctelia in 1982. The lichen is found in Africa, North America, and South America, where it grows on the bark of both hardwood and coniferous trees. Its greenish-grey thallus is covered with tiny white pseudocyphellae – minute holes in the thallus surface that facilitate gas exchange. Some macroscopic features that help distinguish this species from other related members of the genus include the presence and the structure of the apothecia (sexual reproductive organs), the absence of asexual surface propagules, and the light brown color of the thallus undersurface. Chemically, the presence of lecanoric acid in the medulla and atranorin in the cortex help distinguish it from lookalikes.