As an ongoing project I am hoping to catalogue the lichen of my home in Longmont. Completely devoid of natural substrates lichens have found their way to survive in the urban landscape. Lessons here likely apply to similar urban habitats along the Front Range.
Substrates
All of the lichen substrate in Longmont has been placed there by humans. The farmland around the town is nearly devoid of lichens however lichens find their way to survive in this habitat.
Bark – Perhaps the only natural substrate around planted trees often harbor lichens. The yellow wash on trees is almost certainly Xanthomendoza fallax anywhere in the city. On hardwoods Physciella melanchra is nearly always also present.
Wood – By far the substrate with the most diversity, exposed wood has both lichens normally associated with rock substrates and also bark. Weathered fence can often be covered in lichens. Protoparmeliopsis species, R. elegans, and Candelariella sp., dominate foothill granite and surprisingly also dominate fenceposts in the right conditions. Even Rhizoplaca can be found!
Cement – The joys of suburban lichen even include looking at old cement. Especially productive near waterways cement often has the lichens mentioned above for wood. Also common are likely multiple species of the old Caloplaca genus and Acarospora strigata. Both of those lichens even thrive on older patches of sidewalk.
Rock – I have chosen to exclude most rock from the list, as many yards contain “moss rocks.” Purchased specifically due to the lichens already growing on them. These lichens likely supply the spores of many of the colonies on wood and cement.
An Annotated List
Acarosporaceae
Acarospora strigata – common on cement, even sidewalks
Caliciaceae
*Dimelaena oreina* – Present on transplanted “moss rocks.” I have yet to see it grow freely.
Physciaceae
Physcia sp. – Uncommon to rare on trees (pine and hardwood) and wood
Physciella melanchra – Common on hardwoods, very rare on wood and pine
Lecanoraceae
Protoparmeliopsis muralis – Uncommon on cement and wood
Protoparmeliopsis garovaglii – Uncommon on cement and wood
Myriolecis sp. – Likely multiple species present. Uncommon on cement and wood
Lecanora (senso lato) sp. – Rare, at least one species on pine and wood near pine.
Parmeliaceae
Xanthoparmelia sp. – Very rare on wood. So far on non-soridate found.
Flavopunctelia soredica – Single young specimen found on wood.
Teloschistaceae
Rusavskia elegans – Common on cement, infrequent on wood.
Xanthomendoza fallax – Abundant on bark, uncommon on wood
Xanthomendoza sp. 1 – Unusual soredate specimen on wood lacks “hoods” of fallax
Xanthomendoza sp. 2 – Small young specimen on wood, non-soredate, X. montana?
Candelariaceae
Candelariella aurella – Uncommon but generally present on heavily colonized trees, also some lichens presumed to be this species on wood.
*Candelariella rosulans* – Tentative ID of this species on wood. Likely this and C. vitellina occur.
Colorado Lichens and Friends 