Most people know Sulfur Cinquefoil as the plant that looks like marijuana but has yellow flowers. I described it that way on a recent weed walk at our farm and the 14 year old daughter in the group said "Oh yeah! I know that one." The look she got from her mother was priceless.
Most conservation departments want this plant gone and one state even has a "Wanted Dead NOT Alive" poster penned just on cinquefoil's behalf.
Before pulling all of these plants or spraying them however, consider their benefit.
The sweat bee's lay their eggs on the sulfur cinquefoil, aphids are attracted to the plant AND the larvae of the sweat bees eat aphids with wild abandon.
Sweat bees are also called Syrphid flies. From Illinois Wildflowers "The nectar and pollen of the flowers attract Halictid bees, masked bees (Hylaeus spp.), Andrenid bees, Syrphid flies, and small butterflies. Two aphids, Chaitosiphon fragaefolii and Macrosiphum pseudorosae, suck sap from Potentilla spp. (Cinquefoil species), while the larvae of a moth, Tinagma obscurofasciella, are leaf-miners. Some grasshoppers, such as Melanoplus borealis (Northern Grasshopper), feed on the foliage. "
Sweat bee "Larvae are predators on aphids, caterpillars, mealybugs, scale, thrips, corn borers, and corn earworms" - from dirtdoctor.com
We typically leave all "weeds" that aren't specifically in the way in the garden, so to some it looks weedy. However, all of the weeds are there to either attract beneficial insects, trap pests (or in this case both) or to benefit the soil.
If you are worried about this plant taking over, then when the flower head is spent cut it off before it fruits. This plant can grow through the root system too however. But tilling or pulling the weed and breaking the root off will result in propogation as well. I've read the fruit is quite tasty, but we've never tried it.
Please take a good look at the sweat bee larvae. It looks like it might be a bad guy and our reaction is usually to squish all wormy looking things found in the garden. Get to know the bugs there and instead of dread after seeing every bug, you'll be so happy when you see the ones that can work with you.