''Sidalcea oregana'' var. ''calva'', the Wenatchee Mountains checker-mallow, is a very rare flowering plant

variety Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

that occurs only in five locations in the

Wenatchee Mountains The Wenatchee Mountains are a range of mountains in central Washington State, United States of America. A major subrange of the Cascade Range, extending east from the Cascade crest, the Wenatchee Mountains separate the drainage basins of the ...

Chelan County, Washington Chelan County (, ) is a List of counties in Washington, county in the U.S. state of Washington (state), Washington. As of the 2020 United States census, 2020 census, its population was 79,074. The county seat and largest city is Wenatchee, Washi ...

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 U.S. state, states, a Washington, D.C., federal district, five ma ...

. The plant has been placed on the Endangered species list. It is the rarest known plant in

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

state. ''Sidalcea oregana'' var. ''calva'' is a perennial herb in the mallow family

Malvaceae 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 ...

. The species has a stout

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 ...

that branches at the rootcrown and gives rise to several stems that are 20 to 150 centimeters (8 to 60 inches) tall. Plant stems vary 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 o ...

(lacking hairs and glands) to

pubescent The adjective pubescent may describe: * people or animals undergoing puberty * plants that are hairy, covered in trichomes * insects that are covered in setae In biology, setae (singular seta ; from the Latin word for "bristle") are any of a ...

(hairy) or

stellate Stellate, meaning star-shaped, may refer to: * Stellate cell * Stellate ganglion * Stellate reticulum * Stellate veins * Stellate trichomes (hairs) on plants * Stellate laceration or incision Wound#Open * Stellate fan-shaped Espalier (one form ...

(with star-shaped hairs) below and are finely stellate above. The leaves are somewhat thick and fleshy with long petioles (leaf stalks). The leaves are dimorphic (have two forms) with the lower (basal) leaves having more shallow lobes. The flowers have light- to deep pink petals 1 to 2 centimeters (0.4 to 0.8 inch) long. The flowers are borne on stalks ranging from 1 to 10 millimeters (0.04 to 0.4 inch) in length. The

calyx Calyx or calyce (plural "calyces"), from the Latin ''calix'' which itself comes from the Ancient Greek ''κάλυξ'' (''kálux'') meaning "husk" or "pod", may refer to: Biology * Calyx (anatomy), collective name for several cup-like structures ...

(outer whorl of floral parts) ranges from uniformly finely stellate to bristly with a mixture of longer, simple to four-rayed, spreading hairs sometimes as long as 2.5 to 3 millimeters (0.1 to 0.12 inch). 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 ...

(arrangement of the flowers) consists of one to several loosely flowered

raceme A raceme ( or ) or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the sh ...

s (stalked flowers arranged along a single stem) ''S. oregana'' var. ''calva'' is similar in appearance to ''S. oregana'' var. ''procera'', which occurs in the same geographic region. ''S. oregana'' var. ''calva'' can be distinguished from var. ''procera'' by the presence of the hairs on the margins of the calyx lobes and by its large, somewhat fleshy, basal leaves, which are smooth to the touch on both surfaces. The historical range covered an area of approximately 17.7 by 4.8 kilometers (11 by 3 miles), extending south-southeasterly from

Leavenworth, Washington Leavenworth is a city in Chelan County, Washington, United States. It is part of the Wenatchee−East Wenatchee Metropolitan Statistical Area. The population was 2,263 at the 2020 census. The entire town center is modeled on a German Bavarian ...

, to the area now known as Camas Meadows. Most of the historical records of this species are based upon occurrences in the

Icicle An icicle is a spike of ice formed when water falling from an object freezes. Formation and dynamics Icicles can form during bright, sunny, but subfreezing weather, when ice or snow melted by sunlight or some other heat source (such as ...

and Peshastin Creek watersheds.

References

{{Taxonbar, from=Q7507990 oregana var. calva Flora of Washington (state) Endemic flora of the United States Endangered flora of the United States Plants described in 1957