|A Dozen Common and Conspicuous Lichens of the Georgia Piedmont
1. Candelaria concolor
Minute foliose, yellow or yellow-green on rocks and bark, sorediate
C. concolor is the bright yellow stain on city and suburban trees.
Similar species: although unrelated, lichens of the genus Chrysothrix resemble Candelaria in color and texture.
2. Canoparmelia texana
Foliose, green-gray, corticolous, closely attached, with laminal soredia.
This pollution-tolerant lichen can be seen on the trunks of dying dogwoods throughout Atlanta.
Similar species: Canoparmelia caroliniana is very similar, but with fine isidia instead of soredia.
Fruticose, terricolous, with bright red apothecia.
These British soldiers look like red-headed match sticks stuck into the ground.
Similar species: Cladonia sobolescens is similar lichen with brown apothecia, and C. chlorophaea, is another ground dwelling lichen that forms green goblets instead of colored clubs.
4. Cladina subtenuis, synonymn: Cladoina subtenuis
Fruticose, terricolous, yellow-green, forming wooly clumps.
A fast-growing lichen, C. subtenuis can be seen growing in bare dirt along roads and highways.
Similar species: C. rangerferina, reindeer lichen, is the same but ashy white.
5. Flavoparmelia caperata
Foliose, yellow-green, corticolous, with laminal soridia.
The Flavoparmelias stand out from the other shield lichens because of the yellowish color, brightening woods and thickets on wet winter days.
Similar species: F. baltimorensis, is a nearly identical lichen that grows on rocks
6. Hypotrachyna livida
Foliose, green-gray, corticolous, closely attached, with large cup-like apothecia.
H. livida seems to prefer twigs and branches to trucks, and often hosts a purple parasitic fungus.
Similar species: the other Southeastern Hypotrachynas are small and inconspicuous, but H. osseoalba glows bright yellow in ultraviolet light.
7. Parmotrema hypotropum
Foliose, green-gray, corticolous, standing up off the bark, with cilia and soredia on its ruffled edges.
The numerous species of shield lichen are one of the many glories of lichenology in the Southeast.
Similar species: P. tinctorum, once the source of a purple dye, has laminal isidia, and wider paler leaves.
8. Parmotrema perforatum
Foliose, geen-gray, corticolous, ciliate, rising up off the bark, with apothecia.
The large brown apothecia, each with a hole shot through the bottom distinguish this, another shield lichen.
Similar species: P. michaxianum, is a related lichen with imperforate apothecia.
9. Punctelia rudecta
Foliose, green-gray, closely attached to bark or rocks, isidiate.
Punctelia have white spots, or puncta on the upper surface of their thalli.
Similar species: Punctelia subrudecta has soredia in place of isidia.
10. Rimelia reticulata
Foliose, green-gray, corticolous or saxicolous, with marginal soredia.
The Rimelia can be separated from the other shield lichens by the net of fine cracks on their upper surface.
Similar species: Rimelia subisidiosa has isidia in place of soredia.
11. Usnea strigosa
Fruticose, green-gray, corticolous, usually with large, hairy apothecia.
Old man’s beard, is the only Southern Usnea with big pale apothecia, and is especially well developed near creeks and rivers.
Similar species: U. rubicunda, lacks apothecia and is wholly, or partially red.
12. Xanthoparmelia conspersa
Foliose, yellow-green, saxicolous, isidiate, black lower surface.
X. conspersa colors Stone Mountain, and other granite outcrops light green, the darker patches are moss, with which lichens compete for sun, space and water.
Similar species: X. plittii, is identical but for its brown undersurface
In the mountains of northeast Georgia, these three lichens, along with those listed above, are common and conspicuous:
1. Platismatia glauca
Foliose, green-gray, the edges sometimes brown, sorediate, in pines.
The Platismatia have the texture of a crumpled-up piece of paper.
Similar species: Platimatia tuckermanii, less often seen in Georgia, has brown apothecia in place of soredia
2. Tuckermanopsis ciliata
Foliose, brown with greenish areas, on twigs and trunks.
Along the edge of this lichen is a row of tiny black spore producing structures called pycnidia.
Similar species: two other species of this genus can only be identified by their chemistry.
3. Umbilicaria mammulata
Foliose, but have only one point of attachment, brown, on rocks.
Some mountain cliffs, at Mount Yonah for instance, are covered with this lichen, which can grow to fourteen inches across.
Similar species: Lasallia papulosa, has a surface of rounded blisters, but grows like an Umbilicaria
The following lichens are common in Georgia’s costal plain.
1. Cladonia evansii, synonym Cladina evansii
Fruticose, white, terricolous.
What looks like fuzzy cauliflower growing in the sand under palms and pines can only be this lichen.
Similar species: Cladonia leporina, also abundant on the sands, is coarser and, on occasion, produces red apothecia.
2. Cryptothecia rubricinta
Crustose, pink and white, or pink white and green, on bark.
This crust, a lichen fused to its substrate, forms thick red patches surrounded by white, green and red rings on bark in swamps and near the coast.
3. Parmotrema praesorediosum
Foliose, green-gray, with marginal soredia, no cilia.
In this shield lichen the outside edges spread out along the bark, while the crinkled, sorediate edges of the central lobes stand upright.
Similar species: P. rampoddense, resembles P. praesorediosum, has long black cilia along its edges.
Apothecia: cup or disk-shaped structures that produce sexually generated spores by which the lichen’s fungal partner reproduces.
Cilia: bristles that grow out of the edges of foliose lichens.
Corticolous: growing on bark.
Isidia; finger-like projections from the lichen body that act as vegetative propagules.
Isidiate: producing isidia.
Laminal: on the surface away from the edges
Marginal: along the edge.
Pycnidia: small black spots, or knobs that produce asexually generated fungal spores
Rhyzines; bristles that attach the lichen to its substrate.
Saxicolous: growing on rock.
Soredia: fine particles of mixed fungal hypae and algae that act as vegetative propagules; they
form in dusty patches on the lichen surface called soralia.
Sorediate: containing soredia
Terricolous: growing on the ground
Thallus; the lichen body