Common Cinquefoil is a native perennial that is initially erect but short, reaching only to 12 inches high, then declining with stems trailing along the ground that root at nodes. These runners (stolons) have fine hair. The stems and runners are green at first but become reddish with age.
The stem leaves are alternate along the stem and are palmately divided into 5 leaflets. Each leaflet is lanceolate in shape and can be up to 3 inches long and 3/4 inch wide; they have coarse teeth except near the base, blunt tips, dark green on top and may have fine hair on the underside. Basal leaves are not always persistent as the plant ages. These are more oval to elliptic overall, palmate with 5 to sometimes 7 leaflets with long hairs.
The inflorescence is a solitary 1/2 inch wide flower on a long, thin stalk that rises from the leaf axils of the stolon nodes.
Flowers have the 5 yellow petals, narrowed at the base and rounded at the tip which may show a notch. The hypanthium is small, only 3–5 mm in diameter. The 5 sepal lobes are green with triangular shape tips that are just shorter than the petals. Immediately beneath the sepals are 5 small bractlets that are as long as but slightly narrower than the sepals - and hairy, as is the flower stalk. There are 20 to 35 stamens with yellow filaments and yellow anthers and these surround a flattened central yellow disk structure supporting thread-like styles of the numerous 20 to 50 carpels.
Seed: Fertile flowers form dry achenes, 0.9 to 1.2 mm long, that are without hair and fall from the plant and are scattered by the movement of the wiry flower stalks.
Habitat: Common Cinquefoil prefers full sun in well drained soils in moist to dry conditions. It spreads primarily by means of its runners and can form colonies. It is primarily found in disturbed areas or, since it is so short, on the edges of taller prairie vegetation. It can be a pest in fields where a cover crop is not sowed.
Names: The genus name, Potentilla, is from the Latin word potens, meaning 'powerful' and refers to the medicinal power of some species of the genus which have medicinally properties. The species, simplex, is a term used to refer to simple unbranched stems. The author name for the plant classification - “Michx.” is for Andre Michaux (1746-1802), French botanist who made many exploring expeditions in the U.S. collecting and cataloguing many species. Two important works of his are the Histoire des chênes de l'Amérique septentrionale (1801 - Oaks of North America), and the Flora Boreali-Americana (2 vols., 1803 - this was published posthumously and included the description of this plant). His son Francois, traveled with him and the father’s notes were later used for the 3-volume North American Sylva, for which Thomas Nuttall provided some supplements. The various common names about 'five fingers' refer to the 5-part leaf. 'Old-field' has to do with habitat as it invades old fields that are not tilled and sown.
Comparisons: This plant is similar to many cinquefoils with the 5 palmate leaflets and yellow flowers. The short height and the stolons should identify this plant except for the similar P. canadensis, or Dwarf Cinquefoil which is smaller and has blunter more ovate leaflets, however, P. canadensis has never been found in Minnesota although both Eloise Butler and Martha Crone thought they had it in the Wildflower Garden - see "notes" below.
Above: The 5 petals have rounded tips, usually with a notch as seen here (1st photo). Behind the petals (2nd photo) are 5 pointed sepals that appear between the petals and attached just under them are 5 bractlets that are slightly narrower. Note the fine hair on the underside of the leaflet.
Below: The reddish color of the older stem runners is visible in the first photo, while in the 2nd photo, you see that the coarse teeth do not reach the base of the leaflets.
Below: 1st photo - The leaves are palmately divided into 5 leaflets that are alternate along the stem. 2nd photo - Plants are short, usually under 12 inches high.
Notes: Common Cinquefoil is not indigenous to the Garden. It was present when Martha Crone prepared her 1951 census. She used the common name of 'Decumbent Five Finger.' Common Cinquefoil in North America is found in eastern Canada and in the eastern half of the U.S. except Florida. Minnesota is at the NW corner of its range. Within Minnesota it is found in the very eastern side of the state from south to north but also in a few counties more westward such as Morrison and Stearns in the central part and Blue Earth and Renville in the south. In the metro it is known in Hennepin, Anoka, Ramsey and Washington counties. There are 18 Cinquefoils in the genus Potentilla that have been reported in Minnesota of which 2 are introductions. Four of those 18 have not been collected and are thought to be erroneous. Of the remaining 14, several are known from only one county. P. simplex is one of three Cinquefoils in the Garden, the other two being P. recta, Rough Fruited Cinquefoil; and P. argentea, Silvery Cinquefoil; and historically we must add P. norvegica, Rough Cinquefoil.
What did Eloise collect? In Eloise Butler's Garden Log she noted planting Potentilla canadensis on October 10, 1917. She sourced the plant from within Glenwood Park which surrounds most of the Garden. As the species has never been collected or reported in Minnesota anytime or anywhere, this is undoubtedly a mis-classification and as it was late fall, the plant was probable P. simplex as described above in 'comparisons'. That leaves one to wonder what Martha Crone had when she listed both plants on her 1951 census. Flora of North America (Ref. #W7, Vol. 9) does state that simplex is often misidentified as canadensis.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"