''Calyptridium pulchellum'',

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...

''Cistanthe pulchella'', is a rare species of flowering plant in the family

Montiaceae Montiaceae are a family of flowering plants, comprising about 14 genera with about 230 known species, ranging from small herbaceous plants to shrubs. The family has a cosmopolitan distribution. The family Montiaceae was newly adopted in the AP ...

. It is known by the common name mariposa pussypaws. 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 els ...

to the

Sierra Nevada foothills :''See Sierra Nevada for general information about the mountain range in the United States.'' The ecology of the Sierra Nevada, located in the U.S. states of California and Nevada, is diverse and complex: the plants and animals are a significant ...

of central

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 ...

, where it is known from only a few scattered occurrences. It grows on barren patches of

granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...

gravel in woodland and grasslands. It is a federally listed threatened species.

Description

It is a very small red-green annual plant radiating spreading stems a few centimeters long. There is a basal rosette of tiny, thick leaves. The

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 ...

is a number of spherical clusters of rose-colored petals and thin

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined ...

s. The fruit is a tiny translucent capsule containing one or two seeds.

Conservation

In 2007, there were about 9 or 10 occurrences of the plant, with some occurrences made up of two or more small populations.USFWS
Mariposa Pussypaws Five-year Review.
December 2007. The total population number varies year to year, generally because of the influence of local weather changes on the

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ...

of seeds and the growth of

seedling A seedling is a young sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle (embryonic root), the hypocotyl (emb ...

s. Past total population estimates varied from 1680 to nearly 3000 individuals.The Nature Conservancy
/ref> Some populations are located on private land and have not been surveyed in many years. Others are quite variable in size, increasing from 58 to 770 individuals, or decreasing from hundreds of plants to only 3. A major threat to this species is

habitat fragmentation Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological proces ...

; populations have been bisected by

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

s, dirtbike trails, and

firebreak A firebreak or double track (also called a fire line, fuel break, fireroad and firetrail in Australia) is a gap in vegetation or other combustible material that acts as a barrier to slow or stop the progress of a bushfire or wildfire. A firebre ...

s. At least two populations are in the middle of residential subdivisions, or on the edges;USFWS
Determination of threatened status for four plants from the foothills of the Sierra Nevada Mountains in California.
''Federal Register'' September 14, 1998. these may be

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

by now. Residential and commercial development continue to claim the habitat, as does the expansion of infrastructure to support the new development, including local services,

utilities A public utility company (usually just utility) is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and ...

, and roads.

Livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to anima ...

are allowed to graze in some areas, but it is unknown if this affects the species. Since most of the populations are small, they are vulnerable to destruction from any one severe local event, such as

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

, and since the populations sometimes fall to very low numbers they are at risk for genetic bottlenecks and

genetic drift Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and there ...

References

External links

Jepson Manual TreatmentPhoto gallery
{{Taxonbar, from1=Q32855927, from2=Q5122280, from3=Q39601267 Montiaceae Endemic flora of California Flora of the Sierra Nevada (United States) NatureServe critically imperiled species