Annual checkerbloom

Description

Sidalcea calycosa is a species of flowering plant in the mallow family known by the common names annual checkerbloom, checker mallow, and vernal pool checkerbloom. The plant is endemic to California, along the North Coast and adjacent Northern California Coast Ranges from Mendocino County to Marin County in the northern San Francisco Bay Area, and in sections of the western Sierra Nevada foothills from Butte County south into Tulare County. It grows in wetland habitats, including marshes and vernal pools, in oak woodland and chaparral openings, grasslands, and coastal salt marsh plant communities. Sidalcea calycosa is a rhizomatous herb growing 30 centimetres (12 in) to nearly 1 metre (3.3 ft) 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 is a dense, showy panicle of several flowers each with five pink, purplish, or white petals up to 2.5 centimeters long. The bloom period is April through September. Sidalcea is a genus (approx. 25 species) of the botanical family Malvaceae. It contains several species of flowering plants known generally as checkerblooms or checkermallows, or prairie mallows in the United Kingdom. They can be annuals or perennials, some rhizomatous. They are native to West and Central North America. In mid- to late summer the clumps of toothed basal leaves produce erect flowering stems, with 5-petalled mallow-type flowers in terminal racemes, in shades of pink, white and purple. Sidalcea is generally diploid (2n = 20), but polyploidy (4n, 6n) also occurs. Annuality appears to have evolved multiple times (4+) within this genus, although an ancestral annual state with annual paraphyly is also possible. Further, evolution rates within annual Sidalcea lineages appear to be faster than those of perennial lineages, at least when examining nuclear ribosomal DNA (internal and external transcribed spacer regions).