It is amazing how much learning a single flower can reveal. Before making this post, this was simply a yellow flower that had a cool leaf shape that we stumbled upon on a walk up north. As it turns out, it is a quite famous plant called St. John’s wort, best known for its claimed healing properties. I don’t know a ton about herbal medicine, but I have read that it is supposed to be harvested right around when we took this photo, as the oils in the flower itself are what is used.
You can most readily ID this by the 5 yellow petals that have small black dots around the edges. The leaves will be 1-2 inches long and have tiny translucent holes in them, where you can see light shine through if you hold it up to the light.
Traditionally, St. John’s wort has been used to treat inflammation or for minor cuts, but has been tested as a treatment for depression, and it has also been looked at as an application to reduce scarring after surgery. It is also known to have a side effect of causing photosensitivity in mammals that consume it. It is a native of Europe, and has been causing problems out west, where it has been taking over pastures in some areas, causing light sensitivity in the cows that are grazing on it.