A friend gave me a plant she calls bush clematis Davidii. I find nothing online that looks like it. Is about three feet tall, blooms in August and is very hardy. Blooms remind me of a hyacinth. Hope this is enough. Thanks, Ron Kvaas
Most likely it is Clematis heracleifolia. See here:
Unfortunately, there are many varieties, so I won't try to pin down better than that. One is Davidiana, but yours doesn't look right for that one.