A worldwide community photographing and learning about wildlife
Lysimachia thyrsiflora
Small yellow flowers are about 1 cm (1/2 in) across and grow along the main stem of the plant. The plant is about 50 cm (18 in) tall. The leaves are opposite, and long and thin, a bit like goldenrod.
Growing along the edges of a rail trail where it goes through wetland so the ground is rocky but it gets lots of water.
I agree with Alison. I don't know this plant but it is not Hypericum perforatum.
Don't think that's it. St. John's Wort grows here, but the flowers have larger petals.