Indian hemp, Apocynum cannabinum, is a close relative of spreading dogbane. It has smaller, paler, more numerous flowers. It's always fun to find the hybrid between the two, Apocynum x floribundum. It is variable, sometimes more resembling one parent, sometimes the other. This one leans toward dogbane. It appears the craneflies (or whatever they are) enjoyed this one even more than I. This too was at Ives, growing in the fen. The dogbane image was from dry open uplands.