Potentilla recta -- California

Potentilla recta is native to the eastern Mediterranean region of Eurasia. Potentilla recta is naturalized outside its native range in Australia, New Zealand, Canada, US, Japan, Argentina, areas of middle Asia, and areas of Europe. Potentilla recta is found in all lower US states except for Arizona and Utah (USDA). In Montana Potentilla recta infestations were found in 31 different habitat types including conifer, grassland, shrubland, and seasonal wetland ecosystems (NRCS 2007).

Potentilla recta has been found naturalized in California as recorded in Calflora. As reported in GRIN this species has also been naturalized in several areas in a similar climate: Southeastern Australia (New South Wales, Victoria, and Tasmania), New Zealand (South Island), southern Chile (Torres del Paine), US (CA, Pacific Northwest, Appalachian mountains, scattered across New Mexico, Arizona, Nevada, Colorado, Utah, and Nevada), Canada (southern British Colombia, Nova Scotia), across Japan, China (Beijing), western Mongolia (along the Altai Mountain range), along the southeastern border of Kazakhstan, along the Zagros mountains in Turkey and Iran, along the Caucus mountains in Georgia and Armenia, along the Black Sea, southwestern Russian (around the Volga river and along the Ukraine border), throughout Ukraine, and northern Morocco (near Tangier).
In Europe this species occurs densely throughout Spain, France, Germany, Italy, southern Poland, Greece, and eastern Bulgaria. This species is also scattered across Austria, Czechia, Slovakia, Hungary, Scotland, and central and eastern Ireland.

In Montana Potentilla recta infestations were found in 31 different habitat types (NRCS 2007).

Potentilla recta is on invasive species lists in the US and Canada. Potentilla recta displaces native plants and reduces the carrying capacity for livestock and ungulate wildlife in rangelands (NRCS 2007).

This species is listed as a noxious weed in states with similar climates: California, Montana, Nevada, Oregon, Washington, and Colorado (Invasive Plant Atlas, MSU). This plant is also listed as invasive by the National Park Service Mid-Atlantic Invasive Plant Management Team, which covers twenty-one units in Maryland, Pennsylvania, Virginia, and West Virginia, which match the climate map along the Appalachian range. This plant is listed as invasive in British Columbia, Canada, which, in the southern portion, matches the climate map. Potentilla recta displaces native plants and reduces the carrying capacity for livestock and ungulate wildlife in rangelands (NRCS 2007).

Potentilla indica is invasive in West Virginia, which areas along the Appalachian mountains match the Climate Matching map (Invasive Plant Atlas). Potentilla anglica is naturalized in Tasmania, Australia, which is a similar climate (GBIF). Several non-native potentillas (Potentilla anglica, P. norvegica, and P. reptans) have naturalized in California but are not currently considered invasive (Calfora).

Yes, most occurrences are within the Climate Matching map: Southeastern Australia (New South Wales, Victoria, and Tasmania), New Zealand (South Island), southern Chile (Torres del Paine), US (CA, Pacific Northwest, Appalachian mountains, scattered across New Mexico, Arizona, Nevada, Colorado, Utah, and Nevada), Canada (southern British Colombia, Nova Scotia), across Japan, China (Beijing), western Mongolia (along the Altai Mountain range), along the southeastern border of Kazakhstan, along the Zagros mountains in Turkey and Iran, along the Caucus mountains in Georgia and Armenia, along the Black Sea, southwestern Russian (around the Volga river and along the Ukraine border), throughout Ukraine, and northern Morocco (near Tangier). In Europe this species occurs densely throughout Spain, France, Germany, Italy, southern Poland, Greece, and eastern Bulgaria. This species is also scattered across Austria, Czechia, Slovakia, Hungary, Scotland, and central and eastern Ireland.

There are some occurrences that are outside the Climate Matching map: in northern Europe (Denmark, southern Sweden, southern Finland, throughout the UK, the Netherlands), Canada (New Foundland), and in the US (around the Great Lakes, throughout Arkansas, Okhlahoma, and Missouri).

There are several accounts of Potentilla recta dominating plant communities. A study of 85 infestations in Montana found Potentilla recta in 31 different habitat types including conifer, grassland, shrubland, and seasonal wetland eco-systems (NRCS 2007). Potentilla recta is also an early colonizer following disturbance (Soule and Werner 1981). Potentilla recta persists until extensive woody cover dominates (NRCS 2007). Potentilla recta colonies in Montana expanded to more than 400 contiguous hectares over three years (Rice 1999). It "has been recorded at densities up to 39 flowering plants per m2 at a site in Michigan (Werner and Soule 1976), and up to 75% canopy cover on a site in Montana (Rice 1993)" (Zouhar 2003). Potentilla recta can grow up to 80 cm tall (Zouhar 2003). Potentilla recta is a perennial with a thick, woody caudex, which may enable it to outcompete native plants (NRCS 2007). This species may hybridize with native Potentillas but this has not been documented in the field (Soule and Werner 1981).

Although there is no evidence that Potentilla recta alters historic fire regimes, it can be inferred it has the potential to given its ability to resprout after fire, establish after fire, and displace vegetation. The caudex of Potentilla recta can survive fire and resprout (Zouhar 2003). Fire enhanced the survival of new recruits in Montana (Lesica and Martin 2003). "In general, in ecosystems where Potentilla recta replaces plants similar to itself (in terms of fuel characteristics), it may alter fire intensity or slightly modify an existing fire regime. However, if Potentilla recta is qualitatively unique to the invaded ecosystem, it may have the potential to alter the fire regime" (Zouhar 2003).

There is no evidence that Potentilla recta (sulfur cinquefoil) poses a health risk to humans, animals, or fish; however, it does negatively impact grazing systems. “Sulfur cinquefoil is one of the last plants selected by grazing animals. Utilization on infestations in Montana was measured at less than 1% on 98% of sites sampled. Therefore, the impact of sulfur cinquefoil on rangeland sites is to reduce carrying capacity for livestock and ungulate wildlife. On infested hay meadows, sulfur cinquefoil reduces the quality of hay.” (NRCS 2007). NRCS also states that goats may be effective for grazing management in reducing Potentilla recta if confined to an infestation, but because most livestock would naturally avoid Potentilla recta, this species impacts grazing systems (2007).

There is no evidence of this species forming impenetrable thickets and this is unlikely given its growth form. Potentilla recta is a perennial forb that can grow up to 80 cm tall (Zouhar 2003).

"The species reproduces only by seed (achenes), has a single taproot, and may have several shallow, spreading branch roots but no rhizomes" (Dwire et al 2006). "Plants may form a branched caudex that can occasionally break apart to become separate plants in close proximity" (Soule and Werner 1981). Although this may occur occasionally, it is not evidence of the plant spreading vegetatively from its original location.

Although Potentilla recta can regenerate from its caudex, it is not a method of reproduction. "The species reproduces only by seed (achenes), has a single taproot, and may have several shallow, spreading branch roots but no rhizomes" (Dwire et al 2006). "The caudex has regenerative buds so pulling and grubbing must remove the caudex to be effective" (NRCS 2007). "Plants may form a branched caudex that can occasionally break apart to become separate plants in close proximity" (Soule and Werner 1981). Although this may occur occasionally, it is not evidence of the plant spreading vegetatively from its original location.

Potentilla recta (sulfur cinquefoil) "reproduces only by seed (achenes), has a single taproot, and may have several shallow, spreading branch roots but no rhizomes" (Dwire et al 2006). "Sulfur cinquefoil plants were highly fecund; large plants produced 10,000 seeds" (Lesica and Ellis 2010).

There are multiple accounts of copious seed production. Dwire et al. (2006) reported an average of 6000 seeds per plant with some plants producing up to 15,000 seeds in Oregon. Lesica and Eliis (2010) reported that large plants produced 10,000 seeds.

There is significant germination of seeds without special requirements. Seeds are capable of germination without cold stratification (Baskin and Baskin 1990). Seeds are only noted to require light for germination (Baskin and Baskin 1990). Germination in light was 56% to 69% (Lesica and Ellis 2010).

Potentilla recta (sulfur cinquefoil) "matured in as little as one year" (Lesica and Ellis 2010). "Research indicates sulfur cinquefoil plants can produce seeds during their first year and throughout their life spans at a constant rate” (NRCS 2007).

Potentilla recta has a long flowering and seed production phase. Potentilla recta produced seed from July through mid-October in Northeast Oregon (Dwire et al 2006). The plant flowers from May to August (Calflora).

Potentilla recta (sulfur cinquefoil) has the potential to be dispersed by animals and there is observational evidence of this occurring. "While grazing animals rarely eat sulfur cinquefoil, and feeding by small mammals or birds on sulfur cinquefoil plants or seeds is unknown, more research is needed to determine whether seed could be distributed by birds, small mammals, ungulates, and other grazing animals in the following ways" (Zouhar 2003). Potentilla recta can have a viable seed bank for four years or longer (Rice et al 1991). Because this species produces a seed bank, animals transporting soil in their hooves, may also transport viable seeds. There is observational evidence through personal communication with Marla Knight (Jan 2022) that cattle transport Potentilla recta either in the soil in their hooves or as sticky fragments in the fur of their legs. Marla Knight has observed that Potentilla recta along heavily used trails exiting known infestations where cattle congregate then moves along roads as cattle travel out to civilization in the fall after grazing in wilderness/wildlands (pers comm Jan 2022).

There is evidence against long-distance dispersal of Potentilla recta by wind or water. “The seeds are heavy relative to their size and they have no distinctive structure for wind or animal dispersal other than the narrow-winged margins" (NRCS 2007). NRCS found that "seed-rain patterns suggest populations increase as an advancing front more or less in the direction of prevailing winds,” but this was not long-distance dispersal (NRCS 2007). Dwire et al found that approximately 83% of Potentilla recta seeds were found within 60 cm of their source plants (Dwire et al 2006).

Although there is likely contaminated seed dispersal, there is not enough evidence of this occurring to support a greater confidence level. Potentilla recta seeds can be spread from infested hay meadows when plants with flowers are baled in hay (NRCS 2007). Potentilla recta can have a viable seed bank for four years or longer (Rice et al 1991). Disturbing the soil could result in recruitment from the soil bank. Because Potentilla recta's caudex has regenerative buds, it could be spread within a crop field (NRCS 2007).