spiny-sepaled button-celery

Eryngium spinosepalum is an erect perennial herb growing up to about 75 centimetres (30 in) tall with a thick, hairless branching stem. The leaves are widely lance-shaped to oblong, edged with sharp, pointed lobes, and up to 35 centimetres (14 in) in length. The inflorescence is an array of spherical flower heads each up to 2 centimetres (0.79 in) wide and surrounded by several narrow, pointed bracts which may be edged in spines. The heads bloom in white petals, during April and May.

The annual or perennial herb is endemic to California, where it is native to the eastern San Joaquin Valley (southern Central Valley) and adjacent lower Sierra Nevada foothills. It is a plant of vernal pools, moist grasslands, swales, and similar wetland habitats. It grows at elevations of 100–1,270 metres (330–4,170 ft).