Caulanthus californicus

Caulanthus californicus NatureServe Explorer Species Reports — NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports — Caulanthus californicus ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library — The U.S. Fish and Wildlife Service’s National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.

It is endemic to California, where it has been known only from the San Joaquin Valley and the adjacent eastern slopes of the Central Coast Ranges, including the Carrizo Plain and Cuyama Valley. Its range is dramatically decreased from its historical distribution, and the plant is a federally listed endangered species.

This is an annual herb producing an erect or spreading branched stem which is variable in height. The rounded or oval, toothed leaves are up to 10 centimeters long and clasp the stem, mainly around the lower part. The inflorescence produces several rounded flowers, often only along one side of the stem. Each flower has pouched sepals which are dark purple when new and turn light green to white as the flower opens. The frilly petals inside are nearly white with purple veining. The fruit is a silique up to 6 centimeters long.

This endangered plant once occurred across the San Joaquin Valley and well into the surrounding coastal and Transverse Ranges, as well as the Sierra Nevada foothills. As the Central Valley floor was converted to agriculture on a large scale, the plant was extirpated from there.