Found this growing in Snake Lake Park (Tacoma). Main stem is a more than an inch in diameter and almost horizontal/parallel to the ground. There were multiple vertical shoots coming out of the main stem that were nearly an inch in diameter. Did not see any flowers/fruits.
Lila will be correct. Thought I could see flattened leaf stalks and a tiny puff of catkin top right...but leaves not quite right. 2 + 2 =5! amelanchier alnifolia leaves - Google Search
