Analysis of salazinic, norstictic, and usnic acids in Xanthoparmelia chlorochroa by ultra-performance liquid chromatography/tandem mass spectrometry.

The lichen species Xanthoparmelia chlorochroa is toxic when consumed by domestic sheep, cattle, and Rocky Mountain elk. Clinical signs exhibited by poisoned animals include red urine, ataxia, and muscular weakness that rapidly progresses to recumbency. Elk are unable to recover once becoming recumbent; however, most affected cattle can recover if offered suitable feed shortly following the onset of signs.