What is the name of this plant?
Unfortunately, it's challenging to identify unknown plants prior to flowering and/or seeding. First impressions suggest that these plants may ultimately be shrubs or possibly an invasive plant, giant knotweed.
You could dig one up to take to the Clackamas County Master Gardener office, 200 Warner Milne Road; Oregon City, OR 97045. Office Hours 9 to12 and 1 to 4, except holidays.
If you dig up one of the plants and find that is connected to a sturdy rhizome (underground root), it is most likely the knotweed. In that case, remove both plants and every trace of the root system. Finally, remove any new sprouts you see during the coming year(s).