Plagiobothrys strictus is a rare species of flowering plant in the borage family known by the common name Calistoga popcornflower.

The inflorescence is made up of paired branches bearing several five-lobed white flowers each about half a centimeter wide.

It grows in wet grassy habitat kept moist by runoff from hot springs and pools.

[1] The species is threatened by the disturbance of its grassland habitat; both populations are on privately owned, unprotected land; one of these is situated next to a small airport.

[1] Plagiobothrys strictus is a federally listed endangered species of the United States.