Streptanthus niger

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Streptanthus niger
Streptanthus niger.jpg
Tiburon jewelflower
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Brassicales
Family: Brassicaceae
Genus: Streptanthus
Species:
S. niger
Binomial name
Streptanthus niger

Streptanthus niger is an endangered species within the family Brassicaceae. Like other genus members, this herb has wavy petal margins with perimeter calluses that discourage larval herbivory. [1] This plant is endemic to the Tiburon Peninsula [2] of Northern California, and occurs at elevations below 150 m on serpentine grasslands. [3] The common name for this species is Tiburon jewelflower [4] or black jewelflower. This annual herb blooms in May and June and displays dark purple sepals. The etymology of this genus scientific name derives from the Greek word streptanthus, meaning twisted flower, with reference to the notable wavy margins of the petals. The species name niger relates to the color of the seeds being black, although an alternate account cites the dark color of the petals as the source of the appellation.

Endangered species Species of organisms facing a very high risk of extinction

An endangered species is a species which has been categorized as very likely to become extinct in the near future. Endangered (EN), as categorized by the International Union for Conservation of Nature (IUCN) Red List, is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR).

Brassicaceae family of plants

Brassicaceae or 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, some shrubs, with simple, although sometimes deeply incised, alternatingly set leaves without stipules or in leaf rosettes, with terminal inflorescences without bracts, containing flowers with four free sepals, four free alternating petals, two short and four longer free stamens, and a fruit with seeds in rows, divided by a thin wall.

Herbaceous plant Plant which has no persistent woody stem above ground

Herbaceous plants in Botany, frequently shortened to herbs, are vascular plants that have no persistent woody stem above ground. Herb has other meanings in cooking, medicine, and other fields. Herbaceous plants are those plants that do not have woody stems, they include many perennials, and nearly all annuals and biennials, they include both forbs and graminoids.

Contents

Description

Streptanthus niger is an annual herb attaining a height of 20 to 70 centimeters. The plant architecture may manifest as simple-stemmed or branching in the upper part. Lower portions of the stems are smooth and practically hairless. This self-pollinated plant has dark purple, almost black, flower petals; moreover, the petals have a purple claw and a white blade with a purple midvein. The zig-zag inflorescence pattern is an identifying characteristic; furthermore, the flower is almost closed at its throat. Sepals measure five to seven mm. The characteristic wavy petal margins have calluses that inhibit larval herbivory. The leaves of S. niger appear in a basal manifestation and measure less than nine centimeters in length; leaves are generally oblanceolate in shape, and may appear as coarsely dentate or short-lobed. Chromosomal characterization is 2n=28. This plant is also known for belonging to the mustard family and producing black mustard seeds.

Annual plant Plant that completes its life cycle within one growing season, and then dies

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. In a year there are mainly two types of season ,winter and summer.With respect to these seasons annual plants are categorized into summer annuals and winter annuals. Summer annuals germinate during spring or early summer and mature by autumn of the same year. Winter annuals germinate during the autumn and mature during the spring or summer of the following calendar year.

Self-pollination when pollen from one flower pollinates the same flower or other flowers of the same individual

Self-pollination is when pollen from the same plant arrives at the stigma of a flower or at the ovule. There are two types of self-pollination: in autogamy, pollen is transferred to the stigma of the same flower; in geitonogamy, pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant, or from microsporangium to ovule within a single (monoecious) gymnosperm. Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma. The term selfing that is often used as a synonym, is not limited to self-pollination, but also applies to other types of self-fertilization.

Inflorescence Term used in botany to describe a cluster of flowers

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. Inflorescence can also be defined as the reproductive portion of a plant that bears a cluster of flowers in a specific pattern.

Taxonomy

This species is often considered a subspecies of the bristly jewelflower (Streptanthus glandulosus). [5]

<i>Streptanthus glandulosus</i> species of plant

Streptanthus glandulosus is a species of flowering plant in the mustard family known by the common name bristly jewelflower. It is native to California and southwestern Oregon, where it grows in many types of habitat, including grassland, chaparral, and woodlands. Genetic and other analyses indicate that it is a species complex with ten subspecies which evolved as populations were isolated from each other. The complex includes subspecies previously considered separate species, such as the rare Tiburon jewelflower endemic to the San Francisco Bay Area. Plants in the complex are variable. In general they are annual herbs growing 10 centimeters to over a meter in height. They may be hairless to hairy to bristly. The ephemeral basal leaves have blades borne on winged petioles. Leaves higher on the stem are linear to lance-shaped and clasp the stem at their bases. Flowers occur at intervals along the upper stem. Each flower has an urn-shaped calyx of sepals one half to over one centimeter long which can be most any color from white to yellowish to pink or purple to nearly black. Purple, white, or purple-veined white petals emerge from the tip. The fruit is a straight or curving silique up to 11 centimeters long.

Distribution and habitat

There are only two known colonies of Tiburon jewelflower, both of which occur on the Tiburon Peninsula, with a separation of about three km. One of the populations is in the vicinity of the historic Old St. Hilary's Church. The Federal Register listing document noted that S. niger occurs only on grasslands above shallow serpentine soils involving gentle to moderate southwestern facing slopes. The listing statement further notes that: "Serpentine soils are derived from ultramafic rocks such as serpentinite, dunite, and peridotite, which are found in discontinuous outcrops in the...Coast Ranges". [6] According to the Sacramento Fish and Wildlife Service: "species such as Tiburon jewelflower have adapted to serpentine soils and require them to survive". [7]

Grassland areas where the vegetation is dominated by grasses (Poaceae)

Grasslands are areas where the vegetation is dominated by grasses (Poaceae); however, sedge (Cyperaceae) and rush (Juncaceae) families can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica. Grasslands are found in most ecoregions of the Earth. For example, there are five terrestrial ecoregion classifications (subdivisions) of the temperate grasslands, savannas, and shrublands biome (ecosystem), which is one of eight terrestrial ecozones of the Earth's surface.

Serpentine soil soil type

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 antigorite, lizardite, and chrysotile or white asbestos, all of which are commonly found in ultramafic rocks. The term "serpentine" is commonly used to refer to both the soil type and the mineral group which forms its parent materials.

Serpentinite Hydration and metamorphic transformation of igneous rock

Serpentinite is a rock composed of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Minerals in this group, which are rich in magnesium and water, light to dark green, greasy looking and slippery feeling, are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. The mineral alteration is particularly important at the sea floor at tectonic plate boundaries.

Conservation

The Tiburon jewelflower was first collected by Edward L. Greene in the year 1886 at the site of Old Saint Hilary's Church on the Tiburon Peninsula. Streptanthus niger was designated as endangered by the state of California in the year 1990 and listed by the U.S. federal government five years later. By 1998 a Species Recovery Plan had been prepared to provide more specific protection measures for this endangered dicotyledon. [8] For each of the two known colonies, the population has varied between 25 and 2000 over recent years, indicating the precariousness of the species. The California Native Plant Society has placed S. niger on List 1B (rare or endangered throughout its range).

Dicotyledon group of plants

The dicotyledons, also known as dicots, are one of the two groups into which all the flowering plants or angiosperms were formerly divided. The name refers to one of the typical characteristics of the group, namely that the seed has two embryonic leaves or cotyledons. There are around 200,000 species within this group. The other group of flowering plants were called monocotyledons or monocots, typically having one cotyledon. Historically, these two groups formed the two divisions of the flowering plants.

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<i>Streptanthus albidus</i> species of plant

Streptanthus albidus is a species of flowering plant in the mustard family known by the common name Metcalf Canyon jewelflower. It is endemic to California, where it is known only from the Central Coast Ranges and San Francisco Bay Area. It grows in open areas such as grasslands, often on serpentine soils.

Streptanthus barbatus is a species of flowering plant in the mustard family known by the common name Pacific jewelflower. It is endemic to the southern Klamath Mountains of far northern California, where it occurs in open wooded habitat among Jeffrey Pines, generally on serpentine soils. It is a perennial herb producing a decumbent or erect, sometimes branching stem up to 70 to 90 centimeters long. It is hairless except for some light hairs on the flowers and the bases of the leaves. The largest leaves are at the base of the plant. They are oval with faintly toothed, bristly edges and borne on short petioles. Leaves above these are oval to rounded and may clasp the stem. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepals under a centimeter long with curving petals barely emerging from the tip. The calyx of sepals is whitish, darkening purple in maturity. The petals are purple. The fruit is a long, flat, curving silique which may be 7 centimeters in length.

Streptanthus barbiger is a species of flowering plant in the mustard family known by the common name bearded jewelflower. It is endemic to California, where it is limited to the North Coast Ranges. It grows in woodlands and chaparral habitat, often on serpentine soils. It is an annual herb producing a branching stem up to about 80 centimeters in maximum height. Leaves near the base of the stem are lance-shaped to oval and pointed, usually with toothed edges, the blades measuring up to 7 centimeters long. Leaves higher on the stem may be longer but are narrower and have smooth edges. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of greenish yellow or purple sepals under a centimeter long. Whitish or purple-tinged petals up to a centimeter long emerge from the tip. The fruit is a long, flat, curving silique which may be 7 centimeters in length.

Streptanthus batrachopus is a rare species of flowering plant in the mustard family known by the common name Mt. Tamalpais jewelflower. It is endemic to Marin County, California, where it is known only from Mt. Tamalpais and surrounding terrain. There are fewer than ten known occurrences.

Streptanthus brachiatus is a species of flowering plant in the mustard family known by the common name Socrates Mine jewelflower. It is endemic to the Inner North Coast Ranges of California north of the San Francisco Bay Area. It can be found in chaparral and woodland habitat, often on serpentine soils, in Sonoma, Lake, and Napa Counties. It is a biennial herb producing a branching stem up to about 60 centimeters in maximum height. There is a basal rosette of fleshy purple-green leaves around the base, each with a sharp-toothed, widely lance-shaped blade up to 4 centimeters long. Leaves higher on the stem vary in shape. Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of keeled yellowish or purplish sepals just under a centimeter long. White, purple, or purple-veined white petals emerge from the tip. The fruit is a thin, narrow silique which may be up to 6 centimeters in length.

Streptanthus breweri is a species of flowering plant in the mustard family known by the common name Brewer's jewelflower. It is endemic to California, where it can be found in the coastal mountain ranges from the Klamath Mountains south to the San Francisco Bay Area. Its habitat includes chaparral and woodlands, usually on serpentine soils. It is an annual herb producing an erect, branching stem up to about 80 centimeters in maximum height. It is hairless except for fine hairs on some of the inflorescence parts, and it may be waxy in texture. The basal leaves have oval blades borne on petioles, and the lance-shaped leaves farther 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 sepals under a centimeter long. White, purple, or purple-veined white petals emerge from the tip. The fruit is a narrow, curved silique which may be 9 to 11 centimeters in length.

Streptanthus campestris is a species of flowering plant in the mustard family known by the common name southern jewelflower. It is native to southern California and northern Baja California, where it is known from fewer than 20 occurrences scattered between San Bernardino County, California, and Sierra de San Pedro Mártir in northern Baja. It grows in mountain chaparral, woodlands, and forests, at elevations up to 2300 meters. It is a perennial herb producing a thick, few-branched stem up to 1.5 meters tall or more. The basal leaves have fleshy oval blades with bristly, toothed edges which are borne on petioles. Leaves farther up the stem are lance-shaped with smooth or wavy edges and bases that clasp the stem. Flowers occur at intervals on the upper stem. Each has a bell-shaped calyx of bristle-lined purple sepals with four purple tipped yellow petals emerging from the tip. The fruit is a narrow, curving or straight silique which may reach 14 centimeters in length.

<i>Streptanthus diversifolius</i> species of plant

Streptanthus diversifolius is a species of flowering plant in the mustard family known by the common name variableleaf jewelflower, or varied-leaved jewelflower. It is endemic to California, where it is limited to the Sierra Nevada foothills. It is a resident of woodlands and other foothill habitat. It is an annual herb producing a hairless, waxy stem up to a meter tall. The basal leaves are variable in shape and are often divided into narrow, threadlike segments. Leaves higher on the stem are also variable, having round to lance-shaped blades which clasp the stem at their bases. Flowers occur at intervals along the upper stem, with one or two leaflike bracts at the base of the raceme. Each flower has an urn-shaped calyx of keeled sepals about half a centimeter long and white, yellowish, or purple in color, sometimes with white edging. White, purple-veined petals emerge from the tip. The fruit is a thin, flat, curving silique which may be 8 or 9 centimeters in length.

Streptanthus drepanoides is an uncommon species of flowering plant in the mustard family known by the common name sicklefruit jewelflower. It is endemic to California, where it is known from a scattered distribution throughout several mountain ranges in the northern part of the state, including the Klamath Mountains. It is a resident of chaparral and woodlands, generally on serpentine soils. It is an annual herb producing a mostly hairless, waxy stem up to 40 or 45 centimeters tall. The ephemeral basal leaves have round or oval blades, sometimes edged with teeth. Leaves higher on the stem have fleshy oval blades that clasp the stem, the lower ones each measuring up to 9 centimeters long by 7.5 wide. Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of greenish or yellowish sepals under a centimeter long with whitish or purplish, purple-veined petals emerging from the tip. The fruit is a straight or sickle-shaped curving silique up to 9 centimeters long.

Streptanthus farnsworthianus is an uncommon species of flowering plant in the mustard family known by the common name Farnsworth's jewelflower. It is endemic to California, where it is limited to the woodlands of the Sierra Nevada foothills. It is an annual herb producing a hairless, waxy, purple or purple-tinged stem up to half a meter tall or more. The ephemeral basal leaves have blades up to 15 centimeters long which are each divided into several narrow lobes or leaflets. Leaves higher on the stem have purple lance-shaped blades that generally clasp the stem at their bases. Flowers occur at intervals along the upper stem with one or two leaflike purple bracts at the base of the raceme. Each flower has an urn-shaped calyx of purple sepals up to a centimeter long. Curling purple-veined white petals emerge from the tip of the calyx. The fruit is a straight or curving silique up to 12 centimeters long.

Streptanthus fenestratus is an uncommon species of flowering plant in the mustard family known by the common name Tehipite Valley jewelflower.

Streptanthus howellii is an uncommon species of flowering plant in the mustard family known by the common name Howell's jewelflower. It is endemic to the Klamath Mountains of southern Oregon and northern California. It grows in mountain forests on serpentine soils. It is a perennial herb producing a hairless, often waxy-textured stem up to 70 or 80 centimeters in maximum length. It is generally unbranched. The ephemeral basal leaves have fleshy oval blades with smooth or toothed edges, borne on petioles. Leaves farther up the stem are similar but smaller and narrower, with shorter petioles or none. They do not clasp the stem. Flowers occur at intervals along the upper stem. Each has a calyx of purple sepals under a centimeter long with purple-tipped yellow petals emerging from the tip. The fruit is a thin, smooth, curved silique up to 12 centimeters long.

Streptanthus insignis is an uncommon species of flowering plant in the mustard family known by the common names plumed jewelflower and San Benito jewelflower. It is endemic to California, where it is known only from the Inner Central Coast Ranges. It grows in grassland and chaparral habitat, usually on serpentine soils. It is an annual herb producing a hairy, bristly, branching stem up to about 60 centimeters long. The lance-shaped basal leaves are borne on short petioles. Leaves midway up the stem are longer, and those near the top are shorter. They sometimes clasp the stem at their bases. Flowers occur at intervals along the upper stem. The uppermost flowers are often sterile and different in form. Each fertile flower has a bell-shaped calyx of sepals which is purple or greenish-yellow depending on subspecies. The petals at the tip are purplish or yellowish, also depending on subspecies. The fruit is a flat, straight silique which may be over 11 centimeters long.

Streptanthus vernalis is a rare species of flowering plant in the mustard family known by the common name early jewelflower. It was first observed in the 1970s but not actually described to science until 2005. It is endemic to Lake County, California, where it is known from a single occurrence at Three Peaks near the Napa County line. It is apparently limited to serpentine outcrops in forested and chaparral habitat. Genetic analysis indicates that the species is distinct from other Streptanthus and is most closely related to Streptanthus morrisonii, which it resembles. It is a hairless annual herb producing an erect branching or unbranched stem 2 to 20 centimeters tall. The ephemeral basal leaves have thick, fleshy leaves which are green and unmottled on top and purple on the undersides. Leaves higher on the stem are linear to lance-shaped and lack petioles. Flowers occur at intervals along the upper stem. Each flower has an urn-shaped calyx of sepals which is solid green with no purple or yellowish tinge. The petals emerging from the tip are white without darker veining. The fruit is a flattened straight silique 3 to 5 centimeters long containing orange seeds.

Streptanthus morrisonii is an uncommon species of flowering plant in the mustard family known by the common name Morrison's jewelflower. It is endemic to California, where it is known from the North and Central Coast Ranges. It is limited to serpentine soils in chaparral and forest habitat. It is considered a species complex which includes Streptanthus brachiatus. S. morrisonii is divided into four subspecies and is variable. In general, it is a biennial herb producing a hairless, waxy stem up to 1.2 to 1.5 meters in maximum height, often branching at the tip. The basal leaves have fleshy, lance-shaped blades 3 to 5 centimeters long borne on petioles. The blades are gray-green on the upper surface and purple or purple-mottled underneath. Leaves higher on the stem are variable in shape and become smaller toward the top of the plant. Flowers occur at intervals along the upper stem. Each has an urn-shaped calyx of keeled sepals in shades of yellow-green to purple. The petals emerging from the tip are whitish with purple-brown veining. The fruit is a flattened straight or slightly curved silique up to 8 centimeters long.

Streptanthus oliganthus is an uncommon species of flowering plant in the mustard family known by the common name Masonic Mountain jewelflower. It is native to western Nevada and eastern California, where it grows in the rocky hills east of the central Sierra Nevada. Its habitat includes forest, woodland, sagebrush, and mountain talus. It is a rhizomatous perennial herb producing a hairless, waxy, usually unbranched stem up to about 40 or 50 centimeters in maximum height. The basal leaves have lance-shaped, smooth-edged blades up to 10 centimeters long borne on fuzzy to rough-haired petioles. Leaves higher on the stem have shorter blades which may clasp the stem at their bases. Flowers occur at intervals along the upper stem. Each has a bell-shaped calyx of purple sepals no more than a centimeter long. The petals emerging from the tip are reddish purple or purple-tipped. The fruit is a smooth, flat, straight or slightly curved silique up to 8 to 10 centimeters long.

Streptanthus bracteatus is a species of flowering plant in the mustard family known by the common names bracted jewelflower and bracted twistflower. It is endemic to Texas in the United States.

References

  1. ↑ Kruckeberg & Morrison 1983 Madroño 30:230–244
  2. ↑ Marinero Estates Environmental Impact Report, Tiburon, California, Earth Metrics Inc., prepared for the city of Tiburon, Ca (1989)
  3. ↑ Jepson Manual, University of California Press (1993)
  4. ↑ "Streptanthus niger". Natural Resources Conservation Service PLANTS Database. USDA . Retrieved 4 December 2015.
  5. ↑ Flora of North America: ssp. niger
  6. ↑ Federal Register: February 3, 1995 (Volume 60, Number 23) [Page 6671-6685]
  7. ↑ Sacramento Fish and Wildlife Office profile for Streptanthus niger
  8. ↑ Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area U.S. Fish and Wildlife Service (1998)
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