''Streptanthus breweri'' is a species of flowering plant in the

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

known by the common name Brewer's jewelflower. It is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, where it can be found in the coastal mountain ranges from the

Klamath Mountains The Klamath Mountains are a rugged and lightly populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast R ...

south to the

San Francisco Bay Area The San Francisco Bay Area, commonly known as the Bay Area, is a List of regions of California, region of California surrounding and including San Francisco Bay, and anchored by the cities of Oakland, San Francisco, and San Jose, California, S ...

. Its habitat includes

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

and woodlands, often on

serpentine soil 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 an ...

s. It is an annual herb producing an upright, branching stem up to about 80 centimeters in maximum height. It is hairless except for fine hairs on some of 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 branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

parts, and it may be waxy in texture. The basal leaves have oval blades borne on petioles, and the lance-shaped leaves higher up the stem clasp it at their bases. Flowers occur at intervals along the upper stem, sometimes in a zig-zagging, one-sided array. Each has an urn-shaped calyx of keeled greenish or purplish

sepal 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'' ...

s under a centimeter long. White, purple, or purple-veined white petals emerge from the tip. The fruit is a narrow, curved

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 ...

which may be 9 to 11 centimeters in length. The leaves of the plant sometimes have hardened, orange-pigmented callosities on the blades which are thought to be egg-mimics.Shapiro, A. M. (1981)
Egg-mimics of Streptanthus (Cruciferae) deter oviposition by Pieris sisymbrii (Lepidoptera: Pieridae).
''Oecologica'' 48:1 142-3. Female California White butterflies (''Pontia sisymbrii'' syn. ''Pieris s.'') lay eggs on ''Streptanthus'' leaves, and they choose leaves that have not yet had eggs deposited on them. Each

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

can easily eat a whole plant, and the butterfly performs an "egg-load assessment" to determine the potential competition for its larva. Leaves that have grown callosities, which strongly resemble the orange eggs of the butterfly, are less likely visited by egg-laying females, protecting the plant from

herbivory A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

References

External links

Jepson Manual TreatmentPhoto gallery
breweri Endemic flora of California Flora without expected TNC conservation status {{Brassicales-stub