Aaron's Beard is another name they call St. John's Wort (hypericum as Mick T said).
That plant is one of the hypericum species, but keep in mind that I know of at least 9 variations of St. John's Wort, and it takes a closer examination to know which one it is. My guess, however, would be Hypericum perforatum (called Common SJW). There are two versions that are woody at the bottom and a dwarf version as well. So I think you can rule out those three.