Stellaria irrigua

{{Short description|Species of flowering plant}}

{{Speciesbox

|image =

|status = {{TNCStatus}}

|status_system = TNC

|status_ref = {{cite web |last1=NatureServe |title=Stellaria irrigua |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.140025/Stellaria_irrigua |access-date=30 January 2024 |location=Arlington, Virginia |date=2024}}

|genus = Stellaria

|species = irrigua

|authority = Bunge

|synonyms = {{hidden begin|title = List}}

• Alsine baicalensis Coville
• Stellaria gonomischa B.Boivin
• Stellaria leiosperma Pobed.
• Stellaria subumbellata Edgew.
• Stellaria subumbellata f. villosa H.Chuang
• Stellaria umbellata Kar. & Kir.
• Stellaria weberi B.Boivin
• Stellaria wutaica Hand.-Mazz.

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Stellaria irrigua is a species of flowering plant in the family Caryophyllaceae known by the common names umbrella starwort{{PLANTS|id=STUM|taxon=Stellaria umbellata|accessdate=1 December 2015}} and umbellate starwort. It is native to western North America from Alaska and north-western Canada to the south-western United States, as well as parts of Asia, including Siberia. It grows in subalpine and alpine climates in mountain forests and riverbanks. It is a rhizomatous perennial herb producing a slender prostrate stem up to about 20 centimeters long, sometimes forming clumps or mats. The stem is lined with pairs of oval leaves each up to about 2 centimeters long. The inflorescence is an umbel-shaped array of several flowers each on an arching or erect pedicels. The flower has five pointed green sepals each no more than 3 millimeters long. There are occasionally tiny white petals within the calyx of sepals, but these are generally absent.