| Lepidium jaredii | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Brassicales |
| Family: | Brassicaceae |
| Genus: | Lepidium |
| Species: | L. jaredii |
| Binomial name | |
| Lepidium jaredii | |
Lepidium jaredii is a species of flowering plant in the mustard family known by the common name Jared's pepperweed. It is endemic to California, where it is known from the San Joaquin Valley to just within the central Coast Ranges.
Lepidium jaredii is a mustardlike annual herb growing slender, erect stems up to about 70 centimeters in maximum height. The leaves are lance-shaped and up to 10 centimeters long. There are two subspecies of the plant; ssp. jaredii, Jared's or Carrizo pepperweed, has yellow petals, whereas ssp. album, Panoche pepperweed, has white petals. Subspecies album is validly published, but not currently recognized in Jepson Manual 2.
The species appears to have a strict edaphic affinity for clay soils and particularly those with substantial gypsum and salt accumulation in the lower soil profile. For soils of ssp. album, the parent material is typically a marine shale, especially the Moreno shale formation. This soil is an extreme substrate type in which Lepidium jaredii typically dominates, relatively free of competition with other plant species. The soil is typically 3 to 5 inches of high shrink-swell clay topsoil (smectite clay; hard, cloddy when dry) over several inches of subsoil enriched in precipitated gypsum and salts (powdery when dry). The pH of the soils is typically very acidic (as low as 4.5).
Lepidium jaredii is of conservation concern as both ssp. jaredii and ssp. album have limited ranges. Subspecies jaredii is primarily restricted to Carrizo Plain and primarily at the south end of Soda Lake (Panorama Road) where there is a single very large population varying between several thousand to more than a million plants per year. The habitat is nearly level alkali sink (clay flat). The population is on land owned and protected by the Bureau of Land Management Bakersfield Field Office as Carrizo Plain National Monument. Other smaller populations occur farther north on private land near Kecks Corner in western Kern County. The habitat there is on hill slopes. Numerous widely distributed populations of ssp. album occur on hill slopes in western Fresno County and eastern San Benito County at Panoche Hills, Tumey Hills, Griswold Hills, Ciervo Hills, and Big Blue Hills. Much of its habitat is located on land owned and protected by the Bureau of Land Management Central Coast Field Office.
The southernmost known population of ssp. album is located at Oil Canyon north of the city of Coalinga, while the northernmost population of ssp. jaredii is located near Kecks Corner. There is a separation in the known range of the two subspecies of about 40 air miles.
Fremontodendron californicum, with the common names California flannelbush, California fremontia, and flannel bush, is a flowering shrub native to diverse habitats in southwestern North America.
Lepidium virginicum, also known as least pepperwort or Virginia pepperweed, is an herbaceous plant in the mustard family (Brassicaceae). It is native to much of North America, including most of the United States and Mexico and southern regions of Canada, as well as most of Central America. It can be found elsewhere as an introduced species.
Platanthera yadonii, also known as Yadon's piperia or Yadon's rein orchid, is an endangered orchid endemic to a narrow range of coastal habitat in northern Monterey County, California. In 1998 this plant was designated as an endangered species by the United States government, the major threat to its survival being continuing land development from an expanding human population and associated habitat loss. One of the habitats of Yadon's piperia, the Del Monte Forest near Monterey, California, is the subject of a federal lawsuit, based upon endangerment of this organism along with several other endangered species.
Clarkia gracilis is a species of wildflower known by the common name slender clarkia. This plant is native to the US states of California, Oregon, and Washington, where it is found in coastal, foothill, valley, and low-elevation mountain habitats. The plant is variable across subspecies but is generally an erect slender stem with a few sparse, narrow leaves several centimeters long. It bears an inflorescence of drooping buds which open into bowl-shaped flowers with pinkish lavender petals 1 to 4 centimeters long and bearing a red or white splotch which can appear in the center or at the base of the petal, depending on the subspecies.
Lepidium densiflorum is a species of flowering plant in the mustard family known by the common names common pepperweed and prairie peppergrass.
Lepidium flavum is a species of flowering plant in the mustard family known by the common name yellow pepperweed. It is native to California, Nevada, and Baja California, where it grows in the Sonoran and Mojave Deserts. The species epithet flavum is Latin for yellow and indicates its flower colour.
Lepidium fremontii, the desert pepperweed, is a species of flowering plant in the mustard family which is native to the southwestern United States, where it grows on sandy desert flats and the rocky slopes of nearby hills and mountains. It takes its scientific name from John C. Frémont.
Lepidium latipes is a species of flowering plant in the mustard family known by the common name San Diego pepperweed. It is native to California and Baja California, where it grows in alkaline soils in a number of habitat types.
Lepidium montanum is a species of flowering plant in the mustard family known by the common names mountain pepperweed, mountain peppergrass, mountain pepperwort, and mountain pepperplant. It is native to western North America from Oregon to Montana to northern Mexico, where it can be found in a number of habitats, often on salty or gravelly soils. There are several varieties, many of which are difficult to distinguish.
Lepidium oxycarpum is a species of flowering plant in the mustard family known by the common names forked pepperweed and sharp-fruited pepperweed.
Chrysothamnus viscidiflorus is a species of shrub in the family Asteraceae of the Americas known by the common names yellow rabbitbrush and green rabbitbrush.
Clarkia tembloriensis is a rare species of flowering plant in the evening primrose family, known by the common name Temblor Range clarkia and belonging to the Onagraceae family.
Eremalche parryi is a species of flowering plant in the mallow family known by the common name Parry's mallow.
Lepidium dictyotum is a species of flowering plant in the mustard family known by the common names alkali pepperweed and alkali pepperwort.
Monardella hypoleuca is a species of flowering plant in the mint family, known by the common names thickleaf monardella and white leaf monardella.
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.
Thelypodium integrifolium is a species of flowering plant in the mustard family known by the common names entireleaved thelypody and foxtail thelypodium. It is native to much of the western United States, including the Great Basin and surrounding plateaus and deserts.
Lepidium barnebyanum is a rare species of flowering plant in the family Brassicaceae known by the common names Barneby's pepperweed, Barneby's pepper-grass, and Barneby's ridge-cress. It is endemic to Utah, where there is a single population in Duchesne County. It is a federally listed endangered species of the United States.
Lepidium papilliferum is a rare species of flowering plant in the mustard family known by the common names Idaho pepperweed and slickspot peppergrass. It is endemic to Idaho in the United States, where it is mostly limited to a specific habitat type in the southwestern part of the state. It was federally listed as a threatened species in 2009.
Schoenocrambe argillacea is a rare species of flowering plant in the mustard family known by the common names clay reed-mustard, Uinta Basin plainsmustard, and clay thelypody.
