Regularity: Regularly occurring
Comments: Perennial wetland, Cunningham Marsh in Sonoma County, California, that is acidic and nutrient poor (Johnson and Errter 2010).
National NatureServe Conservation Status
Rounded National Status Rank: NH - Possibly Extirpated
NatureServe Conservation Status
Rounded Global Status Rank: GH - Possibly Extinct
Reasons: Potentilla uliginosa was described in 2010, from material previously recorded as P. hickmanii, another rare plant. Both Potentillas are endemic to California, with 'uliginosa' being known only from the Cunningham Marsh, a perennial wetland in southern Sonoma County. P. uliginosa was described from mateial collected in the 1940s, and has been searched for since, however, no extant material was found. It is possible that this species is extinct, however, there is hope that living plants will either be found in northwestern California or that seeds from a persistent seed bank will germinate (Johnson and Errter 2010).