1a Thallus free-living (loose) on soil
Thallus free-living (loose) on soil
1b Thallus attached, substrate various
2a Thallus brown to black, olive black, pale brown, or grayish brown
Thallus brown to black, olive black, pale brown, or grayish brown
2b Thallus some shade of gray, green, yellow-green, or whitish
3a Cortex lacking; thallus whitish, of minute, delicate pseudopodetia forming a short (generally < 1 cm), leprose-appearing turf; common in many open habitats
3b Cortex present; thallus various
4a Thallus white, gray, olive gray, or brownish white (usnic acid lacking)
Thallus white, gray, olive gray, or brownish white
4b Thallus yellowish green to pale green (containing usnic acid)
Thallus yellowish green to pale green (containing usnic acid)