{{Short description|Species of flowering plant}} {{Italic title}} {{Speciesbox |image = Packeralayneae.jpg |status=G2 |status_system=TNC |status_ref=<ref>{{cite web|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.141097/Packera_layneae|title=''Packera layneae''|website=NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer|author=NatureServe|publisher=NatureServe|location=Arlington, Virginia|access-date=22 May 2023|date=5 May 2023}}</ref> |status2 = LT |status2_system = ESA |status2_ref=<ref>{{cite web|url=https://ecos.fws.gov/ecp/species/4062|title=Layne's butterweed (''Senecio layneae'')|website=Environmental Conservation Online System|publisher=U.S. Fish & Wildlife Service|access-date=22 May 2023}}</ref><ref name=fed>USFWS (18 October 1996). [https://www.govinfo.gov/content/pkg/FR-1996-10-18/pdf/96-26740.pdf#page=1 Determination of endangered status for four plants and threatened status for one plant from the Central Sierran Foothills of California.] ''Federal Register'' '''61'''(203):54346–54358. Accessed 23 May 2023.</ref> |taxon = Packera layneae |authority = (Greene) W.A.Weber & Á.Löve |synonyms = ''Senecio layneae'' |}}
'''''Packera layneae''''', known by the common name '''Layne's ragwort''' and '''Layne's butterweed''', is a rare species of flowering plant in the aster family.
==Distribution== The plant is endemic to California, where it is only known from the western slopes of the northern Sierra Nevada foothills. Small populations are found in Yuba, Tuolumne, and Butte Counties, and in the Pine Hill Ecological Reserve in El Dorado County.<ref>[http://www.rareplants.cnps.org/detail/1466.html CNPS−California Native Plant Society: Inventory Plant Detail for ''Packera layneae'']</ref>
==Description== ''Packera layneae'' is a perennial herb producing an upright stem or a small cluster of stems up to 70 centimeters tall. The thick leaves have wide lance-shaped blades a few centimeters long which are borne on long petioles; smaller leaves occur higher up the stems.
The inflorescence bears several flower heads containing many yellow disc florets and several narrow yellow ray florets each up to 1.6 centimeters long.
==Habitat== ''Packera layneae'' grows in cismontane chaparral and oak woodlands habitats of the California Interior chaparral and woodlands ecoregion, often on serpentine soils and weathered gabbro.
===Conservation=== The plant faces several threats and was federally listed as a threatened species in 1996.<ref name=fed/>
The plant grows in chaparral and woodlands habitats that are dependent on a fire ecology of periodic wildfires. Fire suppression efforts alter available sunlight for germination and ongoing growth, and delay the natural 'biomass maintenance' of all plants in this ecosystem.<ref name=fed/> Other threats include development, mining, off-road vehicle use, grazing, and the increasing presence of invasive plants.<ref name=fed/><ref>[http://www.northcoastcnps.org/cgi-bin/inv/inventory.cgi/Go?_id=packera_layneae&sort=DEFAULT California Native Plant Society Rare Plant Profile] {{webarchive|url=https://web.archive.org/web/20120326174738/http://www.northcoastcnps.org/cgi-bin/inv/inventory.cgi/Go?_id=packera_layneae&sort=DEFAULT |date=2012-03-26 }}</ref>
==See also== *List of plants of the Sierra Nevada (U.S.) *{{C|Flora of the Sierra Nevada (United States)}} *{{C|Natural history of the California chaparral and woodlands}}
==References== {{Reflist}}
==External links== {{Commons}} *[http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?609,1784,1819 Jepson Manual Treatment of ''Packera layneae''] *[https://plants.usda.gov/java/profile?symbol=PALA41 USDA Plants Profile for ''Packera layneae''] *[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250067255 Flora of North America: ''Packera layneae''] *[http://calphotos.berkeley.edu/cgi/img_query?query_src=photos_index&where-taxon=Packera+layneae ''Packera layneae'' — UC Photos gallery]
{{Taxonbar|from=Q7122966}}
layneae Category:Endemic flora of California Category:Flora of the Sierra Nevada (United States) Category:Natural history of the California chaparral and woodlands Category:Natural history of Butte County, California Category:Natural history of El Dorado County, California Category:Natural history of Tuolumne County, California Category:Yuba County, California Category:Threatened flora of California Category:Taxa named by Edward Lee Greene
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