I just discovered Vaughn Williams' composition, In the Fen Country. That one I had to hear! But it didn't strike the chord I hoped for. Still, it cries out for another fen flower. But this is not a dedicated one. American vetch grows in fens, but also in a wide variety of other habitats. It clambers over other plants, so it doesn't stand out too much on its own. Kind of like that piece of music. The flowers are about 2/3 inch long. It grows in AK, AZ, CA, CO, IA, ID, IL, IN, KS, MD(X), MI, MN, MO, MT, ND, NE, NJ, NM, NV, NY, OH, OK, OR, PA, SD, TX, UT, VA, WA, WI, WV, WY, AB, BC, MB, NT, ON, QC(L), SK, and YT. Ives Fen Preserve, Lenawee Co MI, 5/13/12.