Distribution:
Ranunculus acriformis, also known as the Autumn buttercup, exists as three different variations in the Intermountain West. Var. acriformis is found Colorado and Wyoming at elevations of 1800-2800 m, var. aestivalis in Utah at 2100-2900 m, and var. montanensis in Idaho, Montana, Utah, and Wyoming at 1500-2400 m. As there are only minor morphological differences between the variations this page focuses on var. aestivalis as a representation of the species (1).
Habitat:
This species grows on drier peaty mounds in wet, saline meadow areas (2). It is adapted to occupy the transitional area between Carex communities and the higher, drier meadows (3).
Description:
The autumn buttercup is a flowering herbaceous perennial. Each plant has a cluster of deeply palmate leaves at its base, and typically grows between 1 and 2 feet. It flowers between July and August, with each plant producing 6-10 five-petalled yellow flowers (4). The species name pays tribute to the fact that it flowers late in season (5).
History:
This plant was first discovered in 1894 in Garfield County, Utah. By 1975 efforts to locate the species were unsuccessful and it was thought to have become extinct until 1982 when the species was rediscovered in a wetland area of south-central Utah (4).
Preservation:
This species is currently listed as endangered (6). It is considered to have a high threat level with low potential for recovery (3). At present, this variation has a limited distribution with only two known populations located within Sevier Valley Preserve in Utah (5). During the 1980s this species experienced a drastic decline, believed to be due to grazing and trampling by livestock and habitat modification. However, the continued decline of the population even after the exclusion of livestock from the area lead some researchers to hypothesize that the decreasing population size is actually a result of a plant community shift. This shift is thought to be due in part to the diversion of the natural water source that feeds the area leading to a reduction in moisture levels. The absence of livestock may also play a part in this decline, as the animals' activity could have previously caused disturbances that opened sites for the establishment of buttercup communities (3). The population is also under threat from natural events such as small mammal grazing or potential desiccation of the habitat from abiotic factors (4).
Blossoms of the Autumn Buttercup
Gary Whitney @ Desert News
Autumn Buttercups in the Sevier Valley Preserve
Gary Whitney @ Desert News
Current geographical distribution of Ranunculus acriformis var. aestivalis
CPC National Collection Plant Profile
Flowering Autumn Buttercup plants
Gary Whitney @ Desert News
REFERENCES
- eFloras.org. Ranunculus acriformis in Flora of North America. http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501100. Accessed 2010.
- Utah Division of Wildlife Resources. Autumn Buttercup (Ranunculus Aestivalis). Utah Conservation Data Center. http://dwrcdc.nr.utah.gov/rsgis2/search/Display.asp?FlNm=ranuaest. Accessed: 2010.
- Tilley, D., St. John, L. and D. Ogle. 2010. Plant guide for autumn buttercup (Ranunculus aestivalis). USDA-Natural Resources Conservation Service, Idaho Plant Materials Center. Aberdeen, ID.
- Fish and Wildlife Service. 1991. Autumn buttercup (Ranunculus acriformis var. aestivalis) Recovery Plan. U.S. Fish and Wildlife Service, Denver, Colorado.
- Center for Plant Conservation. 2010. Ranunculus aestivalis. CPC National Collection Plant Profile. http://www.centerforplantconservation.org/collection/cpc_viewprofile.asp?CPCNum=3705. Accessed: 2010.
- U.S. Fish & Wildlife Service. 2010. Species Profile for Autumn Buttercup (Ranunculus aestivalis). Environmental Conservation Online System. http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=Q212. Accessed 2010.
