Marsh pea has a habit similar to its cousin, sweet pea. It twines and clambers over other plants, holding on with curling tendrils. Indians ate the peas, and used the foliage as fodder, particularly for ailing animals. Leaflets can be very narrow, or a half inch wide. Marsh pea grows in open damp areas in AK, CA, CT, DE, GA, IA, IL, IN, KY(T), LA, MA, MD(X), ME, MI, MN, MO, NC, ND, NE, NH, NJ, NY, OH, OK, OR, PA(E), RI, SD, TN(SC), TX, VA, VT(T), WA, WI, WV, AB, BC, MB, NB, NF, NS, ON, PE, QC, SK, and on SPM. Ives Fen Preserve, Lenawee Co MI, 6/18/11.