I know its been a year and a half since this post, but I wanted to post a follow-up. Thanks for the great ID help, everyone.
I tried to get some flower pictures, but every time I saw them bloom, I didn't have my camera. The flowers didn't stick around long. Plus, it doesn't help when you weed-eat around the pond's edges every few weeks. I ended up spotting this plant in 4 different areas around the property - most of them being in small swampy patches that tend to hold water (and tadpoles) in spring, then de-water in the summer heat.
I did get some pics this spring of the same plant in different areas, taking on different growth patterns. You can see them in the pics below.Hypericum mutilum
New growth on the pond's shady banks.
Young sprouts on the left, with the larger shoots on the right and in the back. This is around the pond. I tried these plants in plain old creek sand in my Leopard frog riparium. It did quite well in medium light considering the substrate. Never amounted to much more that what you see in this pic.
Growing much taller here. A small swampy area with a lot of bulrush, and ludwigia. This soil is still moist, but not a muddy mess like in the above picture.
Same swampy area, but here the soil is dried up, and starting to crack. The plant turns a pretty red color, but doesn't die. I returned to this area throughout the summer expecting them to be dead. To my surprise, the leaves (sometimes the stem) would turn much more red than this photo. They had a mix of green and red coloration and continued growth in this red form.
Currently the plants are now getting old enough and branching. Last year I never saw flowers on un-branched individuals. The small yellow flowers were only seen if the plant made to this branched form before the first frost. Hopefully they will bloom soon and I'll get some pics.
Edited by UncleWillie, 24 August 2011 - 10:44 AM.