Your correspondent missed this one and will rely on Doug Bosco's FB post, and pictures, as well as memories of past July Saturdays on the McMahon prairie.
The main target was white sweet clover (Melilotus alba) a tenacious foe that can usually be uprooted (thank jah for some rain recently) but sometimes has to be clipped, usually the bigger stems. Doug reported the sweetclover population was down this year (perhaps drought-related?), but, since it's a biennial, the presence of first-year plants guarantees we'll be back next year.
I've pulled a few of these from Cherry Hill prairie this year, and another volunteer found and removed some at Sundown prairie, this being quite the ubiquitous plant.