''Streptanthus anomalus'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in family

Brassicaceae Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important Family (biology), family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous pla ...

known by the common names Mount Burdell jewelflower and Tcukamos jewelflower. It is endemic to Mount Burdell in

Marin County Marin County ( ) is a county located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. Marin County is ac ...

, California.

Description

''Streptanthus anomalus'' is an

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...

with a simple or branched, erect stem, growing tall. Basal rosette leaves are long,

oblanceolate The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

, dentate, with

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...

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 A raceme () or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the shoo ...

, with

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...

. The calyx is urn shaped, and the

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

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 The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

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

silique A silique or siliqua (plural ''siliques'' or ''siliquae'') is a type of fruit (seed capsule) having two fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit ...

s, 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 Novato (Spanish for "Novatus") is a city in Marin County, California, United States, situated in the North Bay region of the San Francisco Bay Area. At the 2020 census, Novato had a population of 53,225. History What is now Novato was origi ...

in Marin County, California. These occurrences were discovered in 2011, 2012, and 2023.

Habitat

''Streptanthus anomalus'' is endemic to

serpentine soils Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially antig ...

, where it occurs in sparsely vegetated

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

s 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 The Coast Miwok are an Indigenous people of California that were the second-largest tribe of the Miwok people. Coast Miwok inhabited the general area of present-day Marin County and southern Sonoma County in Northern California, from the Golde ...

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 NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, United States, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and ...

status of G1S1, indicating that the species is critically imperiled.

References

anomalus Plants described in 2019 Endemic flora of California {{improve categories, date=January 2025