Family: Rose Family (Rosaceae)
Origin and Distribution: Sulfur cinquefoil is a European native introduced into North America around 1900. It is most often found growing in the northern U.S. in fields, meadows, pastures, roadsides, and waste places. Sulfur cinquefoil prefers gravelly soil containing lime.
Plant Description: Sulfur cinquefoil is a perennial. It is an erect, hairy, generally unbranched plant with yellow flowers and leaves consisting of 5 to 7 coarsely-toothed leaflets. Leaflets are arranged such that they radiate from a common point like fingers on a hand. Sulfur cinquefoil reproduces by seeds.
- Root system - Sulfur cinquefoil has a taproot that is short, branched, and becomes woody with age. The taproot produces coarse, fibrous roots.
- Seedlings & Shoots - The first true leaves are coarsely toothed but not divided until about the fifth leaf, when leaves appear deeply divided into 3, coarsely-toothed leaflets.
- Stems - Stems are leafy, upright, covered with hairs, and about 1 to 3 feet tall. Stems are typically unbranched, but may branch above the point where flowers begin to emerge. A circle of stems forms around the root crown as new shoots emerge over time. Stems can be induced to form roots at their nodes.
- Leaves - Leaves are alternate (1 leaf per node), green and hairy on both sides, and consist of 5 to 7 coarsely-toothed leaflets. Leaflets are oblong, narrow, and 2 to 4 inches long. Leaflets are arranged so that they radiate from a common point like fingers on a hand. Lower leaves attach to stems by way of long stalks (petioles), but upper leaves have very short stalks. A pair of leaf-like appendages (stipules) are located at the base of each petiole where it attaches to the stem.
- Flowers - Flowers appear in clusters at the top of stems. Flowers are 3/4 to 1 inch wide with 5, heart-shaped, pale to sulfur-yellow petals.
- Fruits & Seeds - Dark brown seeds are about 1/20 inch in diameter and have a prominent, netlike surface.
Similar Species: The 5-parted leaves of sulfur cinquefoil resemble those of hemp or marijuana (Cannabis sativa); however, hemp is taller, has larger leaves, and its flowers do not resemble those of cinquefoil. There are several species of cinquefoils that may be confused with sulfur cinquefoil. Rough cinquefoil (Potentilla norvegica) may be distinguished from sulfur cinquefoil by its branched stems, leaves made up of 3 leaflets and smaller flowers. Silvery cinquefoil (Potentilla argentea) can be distinguished from sulfur cinquefoil by its very coarsely toothed leaflets that are silvery below. Common cinquefoil (Potentilla canadensis) and oldfield cinquefoil (Potentilla simplex) can be distinguished from sulfur cinquefoil by their creeping stems (stolons) that can root at the nodes.
Biology: Seedlings emerge in mid- to late spring and also in late summer. Plants flower from June through September. Each sulfur cinquefoil plant produces about 1,650 seeds. Seeds are wind dispersed. Mowing tends to result in shorter plants with more branches and spreading roots. Other cinquefoils are used as ornamentals or planted for soil erosion control.
Toxicity: None known.
Facts and Folklore:
- Potentilla means 'powerful' and refers to the astringent attributes of plants in this genus.
- The common name 'cinquefoil' was derived from the French term for 'five-leaved'.
- Sulfur cinquefoil was named for the sulfur-yellow color of its flowers.
- Cinquefoils are often a problem in the western U.S. because they tolerate drought and most animals avoid eating them.