''Sidalcea calycosa'' is a species of flowering plant in the

mallow family Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar o ...

known by the common names annual checkerbloom, checker mallow, and vernal pool checkerbloom.Calflora Database: ''Sidalcea calycosa''
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Distribution

The plant 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 ...

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 ...

, along the North Coast and adjacent Northern

California Coast Ranges The Coast Ranges of California span from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains. Ph ...

from Mendocino County to Marin County in the northern

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 Gov ...

, and in sections of the western

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

foothills from Butte County south into

Tulare County Tulare County ( ) is a county located in the U.S. state of California. As of the 2020 census, the population was 473,117. The county seat is Visalia. The county is named for Tulare Lake, once the largest freshwater lake west of the Great Lakes. ...

. It grows in

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

habitats, including

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

es and

vernal pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

s, in

oak woodland An oak woodland is a plant community with a tree canopy dominated by oaks (''Quercus spp.''). In terms of canopy closure, oak woodlands are intermediate between oak savanna, which is more open, and oak forest, which is more closed. Although the ...

and

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterrane ...

openings, grasslands, and

coastal salt marsh A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominat ...

plant communities.

Description

''Sidalcea calycosa'' is a

rhizomatous In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow h ...

herb growing to nearly tall. Despite its common name it may be annual or perennial, depending on the subspecies. The leaves have blades deeply divided into narrow linear lobes, almost divided into leaflets. 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 dense, showy

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit In botany, a fruit is the seed-bearing structure in flowering plants that is ...

of several flowers each with five pink, purplish, or white petals up to 2.5 centimeters long. The bloom period is April through September.

Subspecies

The two subspecies are: *''Sidalcea calycosa'' ssp. ''calycosa'' — annual, blooms March to June, below . *''Sidalcea calycosa'' ssp. ''rhizomata'' — Point Reyes checkerbloom, the perennial subspecies, rare and known only from a few swampy areas of the coastline below in Mendocino, Sonoma, and Marin Counties.Calflora: ''Sidalcea calycosa'' ssp. ''rhizomata'' (Point Reyes checkerbloom)
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References

External links

Calflora Database: ''Sidalcea calycosa'' (Annual checkerbloom, Checker mallow)Jepson Manual eFlora (TJM2) treatment of ''Sidalcea calycosa''USDA Plants Profile for ''Sidalcea calycosa'' (annual checkerbloom)UC CalPhotos gallery: ''Sidalcea calycosa''
calycosa Endemic flora of California Flora of the Sierra Nevada (United States) Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the San Francisco Bay Area {{Malveae-stub