''Pentachaeta bellidiflora'', the white-rayed pentachaeta or whiteray pygmydaisy, is a

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

wildflower A wildflower (or wild flower) is a flower that grows in the wild, meaning it was not intentionally seeded or planted. The term implies that the plant probably is neither a hybrid nor a selected cultivar that is in any way different from the w ...

in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Pentachaeta ''Pentachaeta'' is a genus of the family Asteraceae; the entire genus is endemic to California. Of the six species members, at least one, '' Pentachaeta bellidiflora'', is classified as an endangered species. The etymology of the genus name der ...

'' of the family

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 ...

. It is included in both the state and federal lists of

endangered species 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 inv ...

. It is

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 elsew ...

to the

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

of California,

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, and occurs only at altitudes less than . ''P. bellidiflora'' is found chiefly on rocky, grassy areas. The

conservation status The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...

of this

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 ...

was, as of 1999, characterized by a declining population, with a severely diminished and fragmented range. The specific ''bellidiflora'' refers to the similarity of the flowers with those of common daisies (''

Bellis ''Bellis'' () is a genus of flowering plants in the family Asteraceae. The group is native to Europe, the Mediterranean and northern Africa. One species has been introduced into North America and others into other parts of the world. The genus ...

'').

Description

''Pentachaeta bellidiflora'' is a small annual

growing from a slender

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...

, which, although it appears smooth, is actually covered by fine hairs. The sparsely

hairy Hairy may refer to: * people or animals covered in hairs or fur * plants covered in trichomes * insects covered in setae * people nicknamed "the Hairy" * Hairy (gene) See also * Hairies, a fictional people * Haerye ''Hunminjeongeum Haerye'' ...

stems may number between in length and are typically simple, or branching in the lower half of plant. They are erect, generally flexible, and of green to reddish color. White-rayed ''Pentachaeta'' leaves are normally narrowly

linear Linearity is the property of a mathematical relationship (''function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear r ...

, ciliate (fringed with hair) and green, measuring less than long and one millimeter wide. Upper and lower

leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...

surfaces are smooth.P. bellidiflora
in ''Jepson Manual'', University of California Press (1993) The terminal

inflorescence 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 o ...

s number four or five solitary, roughly circular

heads A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...

per plant. Peduncles are wispy, with bell-shaped involucres measuring 3 to 7 millimeters, and they range from

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 ...

to short-haired. Like all of its genus, ''P. bellidiflora'' has green

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 or ...

in two to three generally equal series,

lanceolate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

obovate The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular o ...

, with margins widely scarious (dry and membranous), and a naked receptacle. The yellow corollas are five-lobed, and each of the 16 to 38 disk shaped

floret This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

s (per head) has linear, acute

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

tips. They may be slightly red-tinged underneath. Fruits are 1.5 to 3.0 millimeters in diameter and are generally compressed in an oblong to

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a b ...

shape; they are typically covered with small hairs. The plant presents fragile pappuses with five or fewer slender

bristle A bristle is a stiff hair or feather (natural or artificial), either on an animal, such as a pig, a plant, or on a tool such as a brush or broom. Synthetic types Synthetic materials such as nylon are also used to make bristles in items such as br ...

s, slightly expanded at the base. Flowering season ranges from late March until late June. From a

chromosomal A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

standpoint, the species is

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

, (contains one set of chromosomes from each parent), and has 2n=18.

Distribution and habitat

White-rayed pentachaeta is found in serpentine grassland as well as

valley A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...

and

foothill Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topograp ...

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

. It is currently known only to survive in serpentine

bunchgrass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perennial ...

communities and native

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

s in two small areas of San Mateo County, including populations in

Edgewood County Park Edgewood County Park and Natural Preserve is a 467-acre protected area located in San Mateo County, California, United States, and is best known for its spring wildflower displays. The park receives about 50,000 visitors each year. Description Ed ...

and on San Francisco Water District lands at serpentine outcrops on the eastern slopes of

Crystal Springs Reservoir Crystal Springs Reservoir is a pair of artificial lakes located in the northern Santa Cruz Mountains of San Mateo County, California situated in the rift valley created by the San Andreas Fault just to the west of the cities of San Mateo and H ...

, in the vicinity of State Route 92. It was formerly known to occur from

Marin Marin (French) or Marín (Spanish "sailor") may refer to: People * Marin (name), including a list of persons with the given name or surname * MaRin, in-game name of professional South Korean ''League of Legends'' player Jang Gyeong-hwan (born 19 ...

to Santa Cruz counties. One study declares only one population remains. Prior range is defined by the following

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

maps: Soquel (387B)* 3612188, Santa Cruz (387E) 3612281, Castle Rock Ridge (408A)* 3712221, Big Basin (408B)* 3712222, Davenport (408C)* 3712212, Felton (408D)* 3712211, Woodside (429A) 3712243, San Francisco South (448B)* 3712264,

Montara Mountain Montara Mountain, positioned between the unincorporated community of Montara, California, to the southwest and the city of Pacifica, California, to the north, forms the northern spur of the Santa Cruz Mountains, a narrow mountain range running the ...

(448C)* 3712254, San Mateo (448D)* 3712253,

San Quentin San Quentin State Prison (SQ) is a California Department of Corrections and Rehabilitation state prison for men, located north of San Francisco in the unincorporated place of San Quentin in Marin County. Opened in July 1852, San Quentin is the o ...

(466B)* 3712284, San Rafael (467A)* 3712285, Point Bonita (467D)*.

Conservation

As of the declaration of Federal endangerment status, the finding of the

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

was that the total species population was sufficiently small and fragmented that it was subject to

stochastic Stochastic (, ) refers to the property of being well described by a random probability distribution. Although stochasticity and randomness are distinct in that the former refers to a modeling approach and the latter refers to phenomena themselv ...

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

. Recent habitat destruction by

urban development Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of people ...

off road vehicle An off-road vehicle, sometimes referred to as an overland or adventure vehicle, is considered to be any type of vehicle which is capable of off-roading, driving on and off Pavement (material), paved or gravel surface. It is generally characteri ...

use and actions of highway maintenance crews have been responsible for the severe reduction in range and viability of this species. Population sizes vary from year to year depending on local

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

and competition from

invasive plant An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

s. In 1997, ''P. bellidiflora'' was the subject of a recovery workshop conducted by the

California Department of Fish and Game The California Department of Fish and Wildlife (CDFW), formerly known as the California Department of Fish and Game (CDFG), is a state agency under the California Natural Resources Agency. The Department of Fish and Wildlife manages and protect ...

, where the need for permanently protecting and managing the existing populations, and reintroduction strategies for populations into suitable protected habitat were analyzed. Management and recovery actions for the species have been addressed in the ''

Federal Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area'', finalized in 1998.''The Status of Rare, Threatened, and Endangered Animals and Plants of California, White-rayed pentachaeta'', California Department of Fish and Game Habitat Conservation Planning Branch, 2000

References

External links

U.S. Federal Listing Details for ''Pentachaeta bellidiflora''
{{Taxonbar, from=Q3374879 Endemic flora of California Astereae Critically endangered plants Natural history of San Mateo County, California Endemic flora of the San Francisco Bay Area