Pentachaeta bellidiflora
Encyclopedia
Pentachaeta bellidiflora (White-rayed pentachaeta or Whiteray pygmy daisy) is a California
n wildflower
in the genus
Pentachaeta
of the (Asteraceae
) family. It is included in both the state and federal lists of endangered species
.
It is endemic to the San Francisco Bay Area
of California, United States
, and occurs only at altitudes less than 620 metres (2,034 ft). P. bellidiflora is found chiefly on rocky, grassy areas. The conservation status
of this species
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
).
growing from a slender taproot
, which, although it appears smooth, is actually covered by fine hairs. The sparsely hairy
stems may number between 6–17 cm (2.4–6.7 in) 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
, ciliate (fringed with hair) and green, measuring less than 4.5 cm (1.8 in) long and one millimeter wide. Upper and lower leaf
surfaces are smooth.
The terminal inflorescence
s number four or five solitary, roughly circular heads
per plant. Peduncle
s are wispy, with bell-shaped involucre
s measuring 3 to 7 millimeters, and they range from glabrous to short-haired. Like all of its genus, P. bellidiflora has green phyllaries in two to three generally equal series, lanceolate to obovate, 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 florets (per head) has linear, acute style 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 shape; they are typically covered with small hairs. The plant presents fragile pappus
es with five or fewer slender bristle
s, slightly expanded at the base. Flowering season ranges from late March until late June. From a chromosomal
standpoint, the species is diploid, (contains one set of chromosomes from each parent), and has 2n=18.
grassland as well as valley
and foothill grassland
. It is currently known only to survive in serpentine bunchgrass communities and native prairie
s in two small areas of San Mateo County, including populations in Edgewood County Park
and on San Francisco Water District lands at serpentine outcrops on the eastern slopes of Crystal Springs Reservoir
, in the vicinity of State Route 92
. It was formerly known to occur from Marin
to Santa Cruz counties
. One study declares only one population remains. Prior range is defined by the following USGS 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
(448C)* 3712254, San Mateo (448D)* 3712253, San Quentin (466B)* 3712284, San Rafael (467A)* 3712285, Point Bonita (467D)*.
was that the total species population was sufficiently small and fragmented that is was subject to stochastic
extinction
. Recent habitat destruction by urban development, off road vehicle 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 and competition from invasive plants. In 1997, P. bellidiflora was the subject of a recovery workshop conducted by the California Department of Fish and Game
, 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 United States
Federal Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area, finalized in 1998.
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
n wildflower
Wildflower
A wildflower is a flower that grows wild, meaning it was not intentionally seeded or planted. Yet "wildflower" meadows of a few mixed species are sold in seed packets. The term "wildflower" has been made vague by commercial seedsmen who are interested in selling more flowers or seeds more...
in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Pentachaeta
Pentachaeta
Pentachaeta is a genus of the Asteraceae family; 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 derives from Greek: Penta = five + chaeta = bristle, referring to...
of the (Asteraceae
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
) family. It is included in both the state and federal lists of endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
.
It is endemic to the San Francisco Bay Area
San Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
of California, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and occurs only at altitudes less than 620 metres (2,034 ft). P. bellidiflora is found chiefly on rocky, grassy areas. The conservation status
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
of this species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
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
Bellis is a genus of 15 species of flowering plants in the family Asteraceae, native to Europe and the Mediterranean region and northern Africa. One species has been introduced into North America and others into other parts of the world.-Description:...
).
Description
Pentachaeta bellidiflora is a small annual wildflowerWildflower
A wildflower is a flower that grows wild, meaning it was not intentionally seeded or planted. Yet "wildflower" meadows of a few mixed species are sold in seed packets. The term "wildflower" has been made vague by commercial seedsmen who are interested in selling more flowers or seeds more...
growing from a slender taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
, which, although it appears smooth, is actually covered by fine hairs. The sparsely hairy
Trichome
Trichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
stems may number between 6–17 cm (2.4–6.7 in) 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
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
, ciliate (fringed with hair) and green, measuring less than 4.5 cm (1.8 in) long and one millimeter wide. Upper and lower leaf
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
surfaces are smooth.
The terminal inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s number four or five solitary, roughly circular heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
per plant. Peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
s are wispy, with bell-shaped involucre
Involucre
Involucre may refer to* involucral bract, a bract, bract pair, or whorl of bracts surrounding a flower or inflorescence* a term sometimes misused for the cupule surrounding developing nuts in the Fagaceae...
s measuring 3 to 7 millimeters, and they range from glabrous to short-haired. Like all of its genus, P. bellidiflora has green phyllaries in two to three generally equal series, lanceolate to obovate, 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 florets (per head) has linear, acute style 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 shape; they are typically covered with small hairs. The plant presents fragile pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
es with five or fewer slender bristle
Bristle
A bristle is a stiff hair or feather. Also used are synthetic materials such as nylon in items such as brooms and sweepers. Bristles are often used to make brushes for cleaning uses, as they are strongly abrasive; common examples include the toothbrush and toilet brush...
s, slightly expanded at the base. Flowering season ranges from late March until late June. From a chromosomal
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
standpoint, the species is diploid, (contains one set of chromosomes from each parent), and has 2n=18.
Distribution and habitat
White-rayed pentachaeta is found in serpentineSerpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
grassland as well as valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
and foothill grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
. It is currently known only to survive in serpentine bunchgrass communities and native prairie
Prairie
Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type...
s in two small areas of San Mateo County, including populations in Edgewood County Park
Edgewood County Park
Edgewood County Park and Natural Preserve is a 467-acre protected area located in San Mateo County, San Francisco, United States, and is best known for its spring wildflower displays...
and on San Francisco Water District lands at serpentine outcrops on the eastern slopes of Crystal Springs Reservoir
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 Hillsborough, and I-280...
, in the vicinity of State Route 92
California State Route 92
State Route 92 is an east-west highway in the San Francisco Bay area between Half Moon Bay near the coast in the west and downtown Hayward at its junction with State Route 238 and State Route 185. It is most notable for being the route that traverses the San Mateo Bridge. It has interchanges with...
. It was formerly known to occur from Marin
Marin County, California
Marin County is a county located in the North San Francisco Bay Area of the U.S. state of California, across the Golden Gate Bridge from San Francisco. As of 2010, the population was 252,409. The county seat is San Rafael and the largest employer is the county government. Marin County is well...
to Santa Cruz counties
Santa Cruz County, California
Santa Cruz County is a county located on the Pacific coast of the U.S. state of California, on the California Central Coast. The county forms the northern coast of the Monterey Bay. . As of the 2010 U.S. Census, its population was 262,382. The county seat is Santa Cruz...
. One study declares only one population remains. Prior range is defined by the following USGS 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
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 length of the San Francisco Peninsula that separates...
(448C)* 3712254, San Mateo (448D)* 3712253, San Quentin (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 AgencyUnited States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
was that the total species population was sufficiently small and fragmented that is was subject to stochastic
Stochastic
Stochastic refers to systems whose behaviour is intrinsically non-deterministic. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E...
extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally 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 recover may have been lost before this point...
. Recent habitat destruction by urban development, off road vehicle 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 and competition from invasive plants. In 1997, P. bellidiflora was the subject of a recovery workshop conducted by the California Department of Fish and Game
California Department of Fish and Game
The California Department of Fish and Game is a department within the government of California, falling under its parent California Natural Resources Agency. The Department of Fish and Game manages and protects the state's diverse fish, wildlife, plant resources, and native habitats...
, 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 United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
Federal Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area, finalized in 1998.