Plagiobothrys strictus

Plagiobothrys strictus
Critically Imperiled
Critically Imperiled (NatureServe)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Boraginales
Family: Boraginaceae
Genus: Plagiobothrys
Species:
P. strictus
Binomial name
Plagiobothrys strictus
Synonyms
  • Allocarya stricta
  • Krynitzkia stricta

Plagiobothrys strictus is a rare species of flowering plant in the borage family known by the common name Calistoga popcornflower. It is endemic to Napa County, California, where it is known from only two small locations near Calistoga.

Description

This is an annual herb growing erect 10 to 40 centimeters tall. It is mostly hairless except for the sepals, which have some rough hairs. The leaves are located along the stem and measure 4 to 9 centimeters long. The inflorescence is made up of paired branches bearing several five-lobed white flowers each about half a centimeter wide. The fruit is a ribbed nutlet 1 or 2 millimeters long.

Taxonomy

In 1892 Edward Lee Greene described a new species in the genus Allocarya, a genus that he described in 1887. The accepted name was created in 1923 when Ivan Murray Johnston described it as a species in Plagiobothrys named Plagiobothrys strictus. Together with its genus it is part of the Boraginaceae family. It has no subspecies and three Homotypic synonyms.

Table of Synonyms
Name Year Rank
Allocarya californica var. stricta (Greene) Jeps. 1901 variety
Allocarya stricta Greene 1892 species
Krynitzkia stricta (Greene) Rattan 1898 species

Distribution and habitat

It grows in wet grassy habitat kept moist by runoff from hot springs and pools. The combined area of land containing the two populations was estimated to be less than 80 square meters in 1990. 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.

Endangered status

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

References

  1. ↑ NatureServe (2 October 2026). "Plagiobothrys strictus". NatureServe Explorer. Arlington, Virginia. Retrieved 25 October 2026.
  2. 1 2 3 POWO (2026). "Plagiobothrys strictus (Greene) I.M.Johnst". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 25 October 2026.
  3. ↑ POWO (2026). "Allocarya Greene". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 25 October 2026.
  4. 1 2 USFWS. Endangered and threatened wildlife and plants; Determination of endangered status for nine plants from the grasslands or mesic areas of the Central Coast of California. Federal Register October 22, 1997.