Punctelia rudecta
Punctelia rudecta (Ach) Krog is a common blue-green foliose lichen found on hardwood trees and bark in eastern North America (Fig 1, 2). This species is easily identified by the light underside of the thallus, the relatively large lobes at the edges of the colony, and the small white pores present on the top of the thallus that are distinctive of the genus (Fig. 3, 4). Like many lichens, P. rudecta can be used as an indicator species for pollution levels in an environment. This species has been described as pollution-tolerant, but has also been shown to be a reasonable indicator species of vehicle pollution levels (https://www.amnh.org/learn-teach/young-naturalist-awards/winning-essays2/2007-winning-essays/lichens-as-indicators-of-vehicle-pollution).
Phylum: Ascomycota
Class: Lecanoromycetes
Order: Lecanorales
Family: Parmeliaceae
Genus: Punctelia
Species: rudecta
Figure 1: P. rudecta on a hardwood stick in a pine forest
Figure 2: P. rudecta thallus, where the distinct blue-green color is apparent.
Figure 3: Folious lobes of P. rudecta
Figure 4: P. rudecta thallus where the white “punctures” (pores) that are indicative of the genus are seen
References:
https://www.discoverlife.org/mp/20q?guide=Lichens_USGA
https://plants.usda.gov/core/profile?symbol=PURU2
https://www.amnh.org/learn-teach/young-naturalist-awards/winning-essays2/2007-winning-essays/lichens-as-indicators-of-vehicle-pollution
http://mason.gmu.edu/~jlawrey/CUE/summary
11.18.18