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Excerpts from Jim Conrad's
Naturalist Newsletter
from the January 19, 2014 Newsletter issued from the Frio Canyon Nature Education Center in the valley of the Dry Frio River in northern Uvalde County, southwestern Texas, on the southern border of the Edwards Plateau; elevation ~1750m (~5750 ft); N29.62°, W99.86°; USA
GOLDEN-EYE LICHEN
One of our most handsome and easy-to-identify lichens turned up this week on a dead Texas Liveoak branch. It was a "fruticose" lichen, which means that it had definite stems, as opposed to "crustose" types that form more or less solid sheets growing over surfaces, or "foliose," which are like leaves lying flat on a surface. Our fruticose lichen was a small one, only about an inch tall (2.5cm). Above, you can see its branched, grayish stems and its spectacular apothecia, or fruiting cups, distinctively fringed along their cup margins with eyelash-like cilia, and with the spore-producing cup surfaces a bright yellow-orange.
With such flashy features our lichen was easy to identify as TELOSCHISTES CHRYSOPHTHALMUS, often known as the Golden-eye Lichen. Golden-eye Lichens occur spottily worldwide, as seen on the GBIF Occurrences Page.
On the south coast of England, Golden-eye Lichens were present over a hundred years ago, then became extinct, and now are recolonizing at a good rate, apparently as spores blow across the English Channel from France. Global warming isn't thought to be behind this, since the lichen was present earlier during much cooler times. General consensus is that probably the species is particularly vulnerable to air pollution. Recent environmental laws have cleared the air somewhat, so the lichens are returning.
Of course lichens are "composite organisms" composed of a species of fungus whose hyphae intermingle with cells of an alga and/or cyanobacterium. In the Golden-eye Lichen's case, the photosynthesizing partner, or "photobiont," is the single-celled green algae Trebouxia, which combines with several species of fungus to produce various lichen species.
entry dated April 20, 2023, issued from near Tequisquiapan; elevation about 1,900m, (6200 ft), ~N20.57°, ~W99.89°; Querétaro state, MÉXICO
(~N20.55°, ~W99.89°)
GOLDEN-EYE LICHEN ON MEXICAN CACTUS
The above Golden-eye Lichens occurred spottily on several Tree Cholla cacti in a large, grossly overgrazed, scrubby, grassy area, but not on other cactus species in the area. This lichen isn't particularly common here, but possibly the occasional small lichen patches of this color appearing on mesquite trees represent stalled attempts at colonization.
Up close, unlike the Golden-eyes met with in Texas, stalks and branches are hard to see. In the above picture, near the bottom, left corner a flattish thallus is visible, but it's very unlike those seen atop this page, photographed in Texas.
Thinking our cactus lichen might be a different species from the Golden-eye, on the GBIF Genus Occurrence Page for Teloschistes, via the "explore" option beneath the worldwide distribution map, I saw that the only Teloschistes species with conspicuous cilia on apothecia rims was Teloschistes chrysophthalmus. Moreover, pictures of other of the species, especially in dry environments, often were similar to ours. Our "stunted" cactus individuals seem to have adapted to the aridity here by dispensing with exposed surface area devoted to slender, branched thalli.
Above you see one of several very small patches found around the larger lichen groupings. Presumably they're the beginnings of a new patch. If the patch began with a single ascospore, pycnidiospore or soredium, one wonders about the open spaces between seemingly detached groupings of lichen bodies seen above. I wonder if the explanation may be in the technical description of the species at the LichenPortal.Org website?
There it's said that in Teloschistes chrysophthalmus finely granular soredia consisting of fungal hyphae wrapped around cyanobacteria or green algae cells -- individual soredia being very rare in this species -- join into larger granular "consoridia," which form over the lichen's body, especially on lamina margins and at their tips. It's unclear to me whether that applies to the grainy items abundantly covering the thallus beginnings seen above. If it does, maybe the above separated groupings of thalli formed from numerous soredia released from a degenerating consoridium.
I can't find mention of this brightly colored lichen used as a source of dye. That's not surprising, since the species is so small and, I read, seldom occurring in large numbers. However, the 2007 work by Alejandra T. Fazio and others entitled "Lichen Secondary Metabolites from the Cultured Lichen Mycobionts of Teloschistes chrysophthalmus and Ramalina celastri and their Antiviral Activities" found our lichen "... to contain parietin which exhibits virucidal effects against certain arenaviruses (Arenaviridae)." Arenaviruses usually infect rodents, but occasionally humans, in which at least eight arenaviruses are known to cause such serious diseases as aseptic meningitis and hemorrhagic fever syndromes.