Bright Cobblestone Lichen

IUCN Red List

NatureServe

Minnesota

not listed

Very common in southwestern United States, uncommon in Minnesota

On sandstone and on granite rocks or outcrops; rarely on soil

Crusticose

The vegetative body (thallus) is up to 4″ wide and somewhat variable in form (squamulose). It may be crusty (crusticose), in such close contact with the rock surface (substrate) that it appears sprayed on like paint; more or less leaf-like (foliose), with thin, flat, lobes that are free from the substrate; or cracked (areolate), broken up into pieces (areoles), appearing somewhat like cracked paint, that can be individually removed from the substrate. The areoles may be round or somewhat polygonal, and may form lobes. The upper surface of the thallus is usually bright yellow or greenish-yellow when fresh but may be bleached white with age.

The spore-producing body (apothecia) are tiny, about 1 ⁄32″ (1 mm) in diameter, and have reddish-brown, concave disks.

Sources: 4, 7, 29.

Uncommon
Bright Cobblestone Lichen is very common in southwestern United States. It is the most common yellow member of its genus in the southwest, and one of the most common lichens of any kind in the deserts of Arizona and southern California. It is uncommon in Minnesota, where it has been recorded only in Cottonwood County.