Keys to Lichens of North America: revised and expanded

Key to keys

Key A : Fruticose lichens

Key B : Dwarf fruticose lichens

Key C : Sterile crustose lichens

Key D : Crustose perithecial lichens and lichens with ascomata resembling perithecia

Key E : Crustose script lichens

Key F : Crustose disk lichens

Key G : Squamulose lichens

Key H : Umbilicate and fan-shaped lichens

Key I : Jelly lichens

Key J : Orange to yellow or yellowish green foliose lichens

Key K : Foliose lichens that are not umbilicate, jelly-like, or yellowish

Identification keys to species.