''Lasthenia'', commonly known as goldfields, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of flowering plants

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

. The genus is named after

Lasthenia of Mantinea Lastheneia (or Lasthenia) of Mantinea ( el, Λασθένεια Μαντινική) was one of Plato's female students. She was born in Mantinea, an ancient city in Arcadia, in the Peloponnese. She studied in the Academy of Plato dressed as a m ...

, a cross-dressing female pupil of the

ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

philosopher

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

Description

The goldfield genus comprises annual (rarely perennial) herbs that are either

glabrous Glabrousness (from the Latin '' glaber'' meaning "bald", "hairless", "shaved", "smooth") is the technical term for a lack of hair, down, setae, trichomes or other such covering. A glabrous surface may be a natural characteristic of all or part of ...

or hairy. Stems are typically branched and erect, attaining a height of less than . Their opposite leaves, up to in length, have entire margins and

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

venation.

Inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

s are characterized by solitary heads (sometimes in cymes), with

phyllaries In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one o ...

free or partly fused. The receptacle may present as naked and narrowly conic to

hemispherical A sphere () is a Geometry, geometrical object that is a solid geometry, three-dimensional analogue to a two-dimensional circle. A sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three ...

. The normally yellow ray florets may number 4 to 16, and the ligules are typically yellow as well. The numerous disk florets typically have yellow, 5-lobed corollae. Anther tips manifest as acuminate to triangular. Style tips may be triangular or round and are typically hair-tufted. Fruits are less than across, cylindric to obovoid in shape, and black or gray in color. The pappus may present awns or scales, or infrequently neither. The genus is mostly cross-pollinated, with some

insects Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...

serving as pollinators.

Ecology and horticulture

Goldfield species occur over a range of

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

, such as meadows, shrubland and open forest, but tend towards

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...

conditions. They are commonly found at ephemeral pools and are important plants in coastal regions. They are visited by

Sciaridae The Sciaridae are a family of flies, commonly known as dark-winged fungus gnats. Commonly found in moist environments, they are known to be a pest of mushroom farms and are commonly found in household plant pots. This is one of the least studie ...

fungus gnats for nectar, and it is possible that these animals are key pollinators at least for Contra Costa Goldfields (''L. conjugens''). In

horticulture Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and no ...

, most make hardy

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

s, suitable for flower-beds or borders. Autumn is the best time for sowing the seed, but it may also be sown early in the spring.

Species

There are a total of eighteen

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, seventeen are

endemic Endemism is the state of a species being found 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 found else ...

to North America and one species is only found in

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. Of the seventeen species found in North America, most are endemic to

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. *'' Lasthenia burkei'' – Burke's goldfields (endemic to California,

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and in ...

) *'' Lasthenia californica'' ::'' Lasthenia californica subsp. californica'' – California goldfields (found in northern California and

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

) ::'' Lasthenia californica subsp. bakeri'' – Baker's goldfields (endemic to California) ::'' Lasthenia californica subsp. macrantha'' – perennial goldfields (endemic to California) *'' Lasthenia chrysantha'' –

alkali sink An alkali sink is a salty basin land form. The term may also refer to a North American desert vegetation type (biome) characteristic of that landform.Pam MacKay, Mojave Desert Wildflowers, 2nd Ed., p. 15-16 Rainwater drains to the basin and collec ...

goldfields (endemic to California) *''

Lasthenia conjugens ''Lasthenia conjugens'', commonly known as Contra Costa goldfields, is an endangered species of wildflower endemic to a limited range within the San Francisco Bay Area of the state of California, USA. Specifically this rare species occurs in N ...

'' – Contra Costa goldfields (endemic to California,

) *'' Lasthenia coronaria'' – crowned goldfields, royal goldfields (found in California and northern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

) *'' Lasthenia debilis'' – Greene's goldfields (endemic to California) *''

Lasthenia ferrisiae ''Lasthenia ferrisiae'' is a species of flowering plant in the family Asteraceae known by the common name Ferris' goldfields. It is endemic to the California Central Valley, where it grows in vernal pools and alkali flats. Description ''Lasthe ...

'' – Ferris's goldfields (endemic to California) *'' Lasthenia fremontii'' – Fremont's goldfields (endemic to California) *'' Lasthenia glaberrima'' – smooth goldfields (found in California, Oregon,

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, and

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

) *'' Lasthenia glabrata'' ::'' Lasthenia glabrata subsp. glabrata'' – yellow-ray goldfields (endemic to California) ::'' Lasthenia glabrata subsp. coulteri'' – Coulter's goldfields (endemic to California) *''

Lasthenia gracilis ''Lasthenia gracilis'', the needle goldfields, is an annual plant with yellow flowers that grows in California and Arizona in southwestern United States, and Baja California in northwestern Mexico. It is in the genus '' Lasthenia'' of the family ...

'' – common goldfields (found in California,

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, the

Channel Islands of California The Channel Islands () are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. The four Northern Channel Islands are part of the Transverse Ranges geologic province, ...

, and northern

) *'' Lasthenia kunthii'' – Chilean goldfields (found in vernal pools in

)Ornduff (1966) *'' Lasthenia leptalea'' – Salinas Valley goldfields (endemic to California) *'' Lasthenia maritima'' – maritime goldfields, seaside goldfields (found along the coast and offshore islands and islets from California to British Columbia) *'' Lasthenia microglossa'' – small-ray goldfields (endemic to California) *'' Lasthenia minor'' – coastal goldfields (endemic to coastal and inland California) *'' Lasthenia ornduffii'' – Ornduff's goldfields (endemic to Oregon) *'' Lasthenia platycarpha'' – alkali goldfields (endemic to California)

References

* (2006)
''Lasthenia.'' In ''Flora of North America North of Mexico, Vol. 21: Asteraceae.'' Flora of North America Editorial Committee (eds.). Oxford University Press, New York, New York.
* (1966): A biosystematic survey of the goldfield genus ''Lasthenia'' (Compositae: Helenieae). ''University of California Publications in Botany'' 40: 1-92. * (2004)
Gardening for the Million.
{{Taxonbar, from=Q614059 Asteraceae genera