Eryngium pinnatisectum is an uncommon species of flowering plant in the family Apiaceae, known by the common names Tuolumne eryngo and Tuolumne button celery.[1]
The annual or perennial herb is endemic to central California, within areas of Sacramento County, Amador County, Calaveras County, and Tuolumne County.[2]
It is known from the eastern Central Valley, and adjacent lower Sierra Nevada foothills.[1]
It is a plant of wetlands, in vernal pools, foothill oak woodland (Cismontane woodland), yellow pine forest (Lower montane coniferous forest), freshwater wetlands, and wetland-riparian habitats.[1]
Eryngium pinnatisectum is an erect perennial herb growing up to 0.5m (01.6feet) tall. It has a thick, hairless pale green branching stem.[3]
The greenish-white leaves are long and very narrow, lance-shaped with several sharp lobes, reaching 30 centimeters long.[3]
The inflorescence is an array of spherical flower heads, each surrounded by sharp-pointed, narrow bracts with thickened edges. The pale greenish flowers in the globelike head bloom in white petals.[3] The blooming period is May to August.