upright cinquefoil, rough-fruited cinquefoil, five-finger cinquefoil, yellow cinquefoil
Sulphur cinquefoil is an upright perennial in the Rosaseae (rose) family. The flowers are light yellow with five petals and a darker yellow center. The leaves have 5-7 leaflets and are rough and hairy with toothed margins. The stems are very hairy with quarter inch long hairs that stick out from the stem. It spreads through its abundant seed production.
Height of mature plants
Up to 3 feet tall
May – early July
Sulphur cinquefoil looks very much like the native slender cinquefoil (Potentilla gracilis), and therefore care should be taken when identifying it. The main differences between these two are that the native slender cinquefoil has petals that are darker yellow, the leaves are a bit silvery on the underside, and the hairs are longer and perpendicular to the stem. Before flowering, the leaves are also sometimes mistaken for marijuana, though once the yellow flowers appear it is very easy to distinguish between the two.
Sulphur cinquefoil grows best in sunny, open habitats, so it is likely to grow in meadows, pastures, roadsides, railroads, logged areas, or abandoned lots.
Sulphur cinquefoil is a very aggressive noxious weed that displaces native forbs and grasses, and can even outcompete some other invasive plants. It can degrade the value of pastures and rangelands as it is unpalatable to livestock and wildlife. It is also drought tolerant and very adaptable. A single plant can live 20 years and can produce up to 5000 seeds.
Noxious Weed Listing:
- WeedWise: priority
- State of Oregon: Class B
- State of Washington: Class B
- Four County CWMA: Class A
- Columbia Gorge CWMA: Class B
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