Candleflame Lichen

Candleflame Lichen, also called Lemon Lichen, is a small, very widespread, very common, foliose lichen. It occurs worldwide on all continents, including Antarctica. It occurs throughout the United States, but it is most common east of the Great Plains, and it is absent from the Great Basin.

Candleflame Lichen is found in a wide variety of habitats. It is common in young well-lit forests, but it is less common in mature forests with a dense canopy. It is very tolerant of pollution and is common in urban and suburban areas. When it is the dominant lichen species in an area it is an indication of high nitrogen in the environment. It grows mostly on nutrient-rich bark of trees, especially on maple, ash, willow, and elm. It also grows on debarked wood, fence posts, and walls. It is less common on rock.

The fruiting body is small, less than ⅜″ (1 cm) in diameter, and cushion-like (suborbicular). Adjacent fruiting bodies often merge to form a large mass. The vegetative body (thallus) is leaf-like (foliose) and divided into small, loosely overlapping lobes. The lobes are flattened, about ⅜″ (1 cm) long, and 1⁄128″ to 1⁄64″ (0.5 to 1.0 mm) wide. The upper surface may be flat, wavy, or raised, fan-like. It is lemon yellow to orangish yellow when exposed to the sun, pale to yellowish green in the shade. The margins are finely scalloped. Cortex-free areas of the thallus (soralia), appearing as horizontal, crescent-shaped slits on and near the margins or at the tips of the lobes, produce granular clusters of cells (soredia). The lower surface is white to pinkish. It is held to the substrate by scattered, unbranched, white, root-like structures (rhizines).

Disk-like, spore-producing structures (apothecia) are rare. When present, they are 1⁄128″ to 1⁄64″ (0.5 to 1.0 mm) in diameter. The disk is the color of the thallus but darker. The margin is smooth at first, becoming uneven and granular with age.

Trees

Foliose

Well-lit young forests, urban and suburban areas.

Sources

4, 24, 26, 29, 30, 77, 81.

Very common and widespread

Class
The order Candelariales has traditionally been placed in the subclass Candelariomycetidae of the class Candelariomycetes. A recent genome-level analysis was conducted of symbiotic ascomycetes, fungi that form mutualistic relationships with other organisms (Díaz-Escandón et al., 2022). The authors merged six classes, including Candelariomycetes, and gave the new class the name Lichinomycetes, which is the oldest name among the six. With the merger, the subclass Candelariomycetidae became obsolete.

The move has been widely but not universally accepted. ITIS, MycoPortal, NatureServe, and iNaturalist place Candelariales in the class Lichinomycetes. Index Fungorum, MycoBank, LichenPortal, GBIF, and Catalog of Life place it in the class Candelariomycetes.

Candelaria concolor, lichens of Ouray Colorado USA
Mike's thoughts on plants.

Candelaria concolor, Xanthoria parietina
EcoCorZonneveld

Lemon lichen, Candelaria concolor, North Tampa, Florida.
Mike's thoughts on plants.

Luciearl
9/26/2018

Location: Cass County