This differs from other causes of secondary or heptogenic photosensitization such as that seen in bighead, caused by horsebrush. The photoactive toxins in spring parsley have been identified as furocoumarins, xanthotoxin and bergapten. Spring parsley is a perennial that grows 8-12 cm tall. It gets its name from the finely divided leaves that resemble parsley. The plant has a long taproot.
Spring parsley is a member of the carrot family.
Plants are poisonous from early spring until they mature and dry in early summer. Spring parsley grows on well-drained soils, on rolling foothills, and with sagebrush, pi on pines, and junipers. It occurs at elevations of 1500 to 3500 meters. This is one of the first plants to begin growing in early spring. It flowers from late April to June and disappears by early summer.