Field Key to Brilliant Yellow Foliose Lichens

1        Thallus some shade of yellow, K-; soredia at lobe tips …………………………………………………………. Candelaria concolor

Candelaria concolor

–        Thallus with orange hues, K+ purple…………………………………………………………………… 2

2        Thallus with neither soredia nor isidia; apothecia conspicuous and abundant Rusavskia elegans, Xanthoria hasseana,and Xanthoria parietina

Rusavskia elegans

–        Thallus sorediate; apothecia uncommon……………………………………………………………… 3

3        Soredia produced within marginal “bird nests” bordered by upper  and lower cortices Xanthomendoza fallax

Xanthomendoza fallax

–        Soredia produced at tips and lower margins of upturned lobes.. Xanthomendoza weberi

Xanthomendoza weberi

Xanthomendoza weberi