Goldspeck lichens are orange to yellow crustose lichens that are frequently seen growing on rocks, wood, or other substrates. Missouri has about three species.
- One common Missouri species is the granular goldspeck lichen, Candelariella xanthostigma. It is often seen colonizing sunny, rocky places. You have to get close to see the tiny, darker orange, disk-shaped apothecia (spore-bearing structures) nestled among the crusty, yellow-orange patches of goldspeck lichens. Use a magnifying glass, or use a camera with a good closeup lens.
- Two other goldspeck lichens have been recorded for Missouri: C. reflexa and C. vitellina. The latter is sometimes called the common goldspeck lichen. Specialists apply chemicals (and look for color changes) and examine the spores microscopically to determine species.
Like other crustose lichens, goldspeck lichens are tightly attached to the rock, bark, or other material they grow on. They often look like an old, weathered coat of paint, and the surface may looked cracked or bumpy.
A lichen is an organism that results when a fungus species and an algae species join together. Although the relationship between the fungi and algae is quite intimate and integrated, the lichen that is formed does not much resemble either of the components. Learn more about lichens on their group page.
Similar species:
- Missouri has 23 species of firedot lichens (crustose lichens in genus Caloplaca), and many of these are orange or yellowish. Some species grow in round patterns with edges that are so wrinkled that they appear foliose.
- Orange sunburst lichens (Xanthoria or Xanthomendoza species) can be very common on sunny rocks and tombstones. They have a circular, foliose growth pattern with tiny, branching lobes, but this pattern often becomes obscured when these lichens coalesce into large masses of tiny scale-like fragments and portions break off. For this reason, these could easily be misinterpreted as crustose lichens.
- Candleflame lichen, or lemon lichen (Candelaria concolor) is very small (fingernail-sized), although it can grow in groups covering large areas. Candleflame lichen almost always grows on bark and is a greenish (not orangish) yellow. Numerous granular soredia form at the lobe tips, making it look frilly at the tips. It is a foliose lichen, and you can usually see the delicate rosette pattern, with branching, petal-like lobes, if you look closely. The similar-looking Candelaria fibrosa also occurs in Missouri.
Lichens begin as tiny spots but may grow to cover several square inches. Groups of goldspeck lichens may coalesce to cover large areas.
Statewide.
Habitat and Conservation
Different species prefer rock, wood, tree bark, soil, or other substrates, though some species are generalists that can live in a variety of habitats.
Human Connections
There is some evidence that lichens that grow on tombstones may secrete mildly acidic chemicals onto their substrate and, over a long period of time time, may contribute to the weathering of headstones. For this reason, and to make inscriptions easier to read, cemetery caretakers may clean lichens from tombstones. But there is also evidence that lichen growth might actually protect tombstones from more drastic weathering caused by rain, hail, and so on. Be aware that the tombstone material (type of rock) and its condition, and the different types of lichens, complicate the subject. Since crustose lichens often penetrate into porous stone, it may be impossible to fully remove them from tombstones without damaging the stone. Harsh cleaning chemicals and abrasive methods should be avoided, because they can do more damage than good.
Some people appreciate the softened look lichens give to an old, old cemetery. In the mid-1800s, the celebrated essayist John Ruskin wrote of lichens and mosses in cemeteries: “Meek creatures! . . . laying quiet finger on the trembling stones, to teach them rest. . . . And as the earth’s first mercy, so they are its last gift to us: When all other service is vain . . . the soft mosses and gray lichen take up their watch by the headstone. . . . These do service for ever.”
Lichens contribute to a beautiful landscape. In desert, alpine, tundra, or other rocky habitats, they can coat rocks with a riot of bright colors — neon yellows, oranges, and greens — which intensify after a rain. Goldspeck lichens are one of the groups that are most colorful. In Missouri, good places to see lichens on rocks include glades and the open, rocky tops (balds) of Ozark hills. Visit places like Taum Sauk Mountain, Elephant Rocks State Park, Wildcat Glades, and Lichen Glade Conservation Area.
Ecosystem Connections
People have explored possible medicinal uses for lichens in this genus. Also, some goldspeck lichen species may yield a natural dye for textiles.
Lichens that live on rock are described as “saxicolous” (the prefix “sax” means rock). Ones that live on wood are described as “lignicolous” (as in lignin, a main component of wood). Goldspeck lichens are frequently parasitized by fungi. Fungi, lichens, and other species that live upon lichens are termed “lichenicolous.”
Lichens are pioneer organisms. Over very long periods of time, lichens that live on rocks gradually chemically degrade the minerals that compose the rock, slowly breaking down (weathering) the rock. This contributes to the development of soils. In places where the landscape is almost totally bare rock, lichens begin the process of ecological succession. Once soils are created, mosses, grasses, and other small plants can become established. As soils are built up, these are followed by a succession of communities of larger plants such as shrubs and trees.
Mosses, liverworts, hornworts, and lichens seem rather similar, but these organisms are in very different groups. Mosses, liverworts, and hornworts are small, low plants usually found in damp habitats. Unlike more familiar plants, they lack veinlike structures and do not produce flowers or seeds — instead, they produce spores. Meanwhile, lichens are not plants at all: they are a collection of different fungi that have photosynthetic algae living within their tissues.