| Layia discoidea | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Layia |
| Species: | L. discoidea |
| Binomial name | |
| Layia discoidea | |
Layia discoidea is a rare species of flowering plant in the family Asteraceae known by the common name rayless tidytips, or rayless layia.
Layia discoidea is a local serpentine endemic where it is known only from the Diablo Range in southern San Benito County and far western Fresno County. The known distribution of the species is the New Idria serpentine mass (BLM Clear Creek Management Area) and nearby Laguna Mountain, Hepsedam Peak, and Panther Peak serpentine masses. Layia discoidea is regarded as a strict serpentine endemic with several populations known (as of 2017) to occur on greywacke and chert outcrop and talus at the edge of the New Idria Serpentine Mass near Condon Peak, Sampson Peak, and Idria Reservoir. Typical habitat of the species is serpentine rock outcrop, serpentine talus, and serpentine stream terraces where it grows in full sun with little to no competition from other plant species. The shale and chert outcrop habitat that a few populations of Layia discoidea grows on has similar (analogous) physical and microclimate conditions as the serpentine habitat that the species is primarily found growing.
This is an annual herb growing a small glandular stem to a maximum height of about 20 centimeters. The thin leaves are generally lance-shaped, but the larger leaves on the lower part of the stem are usually lobed. Unlike other Layia species, which are known for their prominent white or yellow ray florets, Layia discoidea has no ray florets or real phyllaries. The flower head is a cluster of many deep yellow disc florets with a base of bractlike scales. The fruit is an achene with a short scaly brown pappus.
Genetic analysis performed on this species suggest that it evolved directly from Layia glandulosa in what may be an example of both allopatric speciation and peripatric speciation. [2] Layia discoidea looks quite different from the white-rayed Layia glandulosa, and it lives in a specialized habitat, but the two species are genetically very similar and produce robust, fertile hybrids when crossed. [3]
Known extant Layia glandulosa populations within the range of Layia discoidea typically have deep yellow ray florets.
Individuals of Layia discoidea occasionally display ray florets that are light yellow in color (see Calphotos and [4] ). Individuals bearing ray florets have been observed in populations at the New Idria, Laguna Mountain, and Panther Peak serpentine masses. It is unclear if the ray florets are a result of hybridization with nearby Layia glandulosa, a genetic mutation, or simply induced by environmental conditions.
Matricaria discoidea, commonly known as pineappleweed, wild chamomile, disc mayweed, and rayless mayweed, is an annual plant native to northeast Asia where it grows as a common herb of fields, gardens, and roadsides. It is in the family Asteraceae. The flowers exude a chamomile/pineapple aroma when crushed. They are edible and have been used in salads and to make herbal tea. Pineappleweed has been used for medicinal purposes, including for relief of gastrointestinal upset, infected sores, fevers, and postpartum anemia.
Ericameria discoidea, called whitestem goldenbush or sharp-scale goldenweed or whitestem goldenbush or sharp-scale goldenweed, is a species of flowering shrub in the daisy family known by the common name whitestem goldenbush. This plant is native to the western United States from California, Oregon, Nevada, Utah, Colorado, Idaho, and Montana.
Lagophylla glandulosa is a species of flowering plant in the family Asteraceae known by the common name glandular hareleaf. It is endemic to California, where it grows in the Central Valley and foothills in chaparral, grassland and woodland habitat. This is an annual herb growing a very thin stem covered in glandular hairs, especially at the top in the inflorescence. The leaves are mostly small, smooth-edged, and glandular-hairy on the top of the stem, with much larger, toothed leaves toward the base. The inflorescence bears flower heads with five bright yellow ray florets, each with three lobes. The center of the head contains six disc florets which are yellow with black anthers. The fruit is a dark brown achene with no pappus.
Layia is a genus of flowering plants in the family Asteraceae known generally as tidy tips, native to western North America. Several are California endemics.
Layia carnosa is a species of flowering plant in the family Asteraceae known by the common name beach tidytips, or beach layia. It is endemic to California, where it lives in beach habitat. It is known from several areas of mostly fragmented coastal habitat, and it was listed as an endangered species in California. On March 31, 2022, the category was changed from endangered species to threatened species by the US Department of the Interior Fish and Wildlife Service.
Layia chrysanthemoides is a species of flowering plant in the family Asteraceae known by the common name smooth tidytips, or smooth layia.
Layia fremontii is a species of flowering plant in the family Asteraceae known by the common name Frémont's tidytips. Both its common name, and its specific epithet are derived from John C. Frémont.
Layia glandulosa is a species of flowering plant in the family Asteraceae known by the common names whitedaisy tidytips and white layia. It is native to western North America south from central Washington (state) to Baja California and east to Utah and Arizona, where it is common in a number of habitat types.
Layia hieracioides is a species of flowering plant in the family Asteraceae known by the common name tall tidytips, or tall layia.
Layia jonesii is a species of flowering plant in the family Asteraceae known by the common name Jones' tidytips, or Jones' layia.
Layia munzii is a rare species of flowering plant in the family Asteraceae known by the common name Munz's tidytips, or Munz's layia.
Layia pentachaeta is a species of flowering plant in the family Asteraceae known by the common name Sierra tidytips, or Sierra layia.
Layia septentrionalis is an uncommon species of flowering plant in the family Asteraceae known by the common name Colusa tidytips, or Colusa layia.
Arnica discoidea is a North American species of arnica in the sunflower family. It is known by the common name rayless arnica because its flower heads have disc florets but none of the showier ray florets. It is native to the woodlands, forests, and chaparral of the western United States (Washington, Oregon, California, and western Nevada.
Camissonia benitensis is a species of evening primrose known by the common names San Benito suncup and San Benito evening primrose. It is endemic to California, where its range includes far southern San Benito County, far western Fresno County, and far eastern Monterey County.
Senecio pattersonensis is an uncommon species of flowering plant in the aster family known by the common names Mono ragwort. and Mount Patterson senecio.
Solidago guiradonis is an uncommon species of goldenrod known by the common name Guirado goldenrod. It is native to the Central California Coast Ranges of central California, in southern San Benito and western Fresno Counties.
Agnorhiza bolanderi is a species of flowering plant known by the common name Bolander's mule's ears. It is endemic to California, where it is known only from a narrow section of the Sierra Nevada foothills about 275 kilometers long from Shasta County to Mariposa County. It grows in chaparral and grassland habitat, usually on serpentine soils.
Packera franciscana is a rare species of flowering plant in the aster family known by the common name San Francisco Peaks groundsel, or San Francisco Peaks ragwort. It is endemic to Arizona in the United States, where it is known only from the San Francisco Peaks in Coconino County. It is threatened by recreational activities in its habitat. It is a federally listed threatened species of the United States.
Leslie David Gottlieb (1936–2012) was a United States biologist described by the Botanical Society of America as "one of the most influential plant evolutionary biologists over the past several decades". He was employed at the University of California, Davis for 34 years, and published widely. In addition to his primary work in plant genetics, Gottlieb was an advocate for rare and endangered plant conservation.
Harrison SP. 2013. Plant and Animal Endemism in California. University of California Press.
