Streptanthus anomalus


Streptanthus anomalus is a species of flowering plant in family Brassicaceae known by the common names Mount Burdell jewelflower and Tcukamos jewelflower. It is endemic to Mount Burdell in Marin County, California.

Description

Streptanthus anomalus is an annual plant with a simple or branched, erect stem, growing tall. Basal rosette leaves are long, oblanceolate, dentate, with ciliate margins, while ovate cauline leaves have distinctive clasping bases. By flowering time, most rosette and proximal leaves are absent, and distal leaves have faded to a greenish yellow. Flowers occur in bracted, one-sided racemes, with pedicels. The calyx is urn shaped, and the sepals are either greenish-yellow or dark wine-red. long petals are exserted from the calyx, with yellow bases, brown to purple blades, and white margins. Stamens occur in either 3 unequal pairs, or with 4 long and 2 short stamens. The upper stamens have fused filaments and sterile anthers. Fruits are siliques, long and wide, with 30-40 seeds. Each seed is long and wide, with a narrow wing.

Range

Streptanthus anomalus is restricted to 3 occurrences on the lower slopes of Mount Burdell, north of the City of Novato in Marin County, California. These occurrences were discovered in 2011, 2012, and 2023.

Habitat

Streptanthus anomalus is endemic to serpentine soils, where it occurs in sparsely vegetated grasslands with thin, rocky soils.

Etymology

The specific epithet "anomalus" alludes to the anomalous possession of bracted inflorescences, which are absent among other members of section Euclisia. "Mount Burdell" refers to the range of the species, while "Tcukamos" is the Coast Miwok name for that geographic feature.

Taxonomy

Streptanthus anomalus was described in 2019. It has been placed in section Euclisia alongside S. glandulosus. It does, however, share some characteristics with S. tortuosus, which suggests a possible hybrid origin.

Conservation

Streptanthus anomalus has been assigned a California Rare Plant Rank of 1B.1 indicating that the species is rare, threatened, or endangered throughout its range.
It has also been assigned a NatureServe status of G1S1, indicating that the species is critically imperiled.