It comes up in the spring, gets about 3.5 ft tall, never blooms & dies back in winter. I've pulled up a lot of it; it grows from an underground thick runner type root system. I think it's a general weed, but want to be sure before I kill it all. I'm trying to eliminate invasives and encourage natives on the property.
Close-up of top click here.
EDIT: Jul 22, 2014 - It is dog bane, a/k/a indian hemp with buds. It did "bud up" and finally bloomed but not large flowers, just barely open little bell-shaped blooms. See also bottom right link on this page; branching near top, somewhat reddish stems. Dogbane is a nectar source for adult monarchs (and many others), but NOT host plant for the monarch caterpillar. It is hosting an unidentified communal web that produces a small green, becoming a fuzzy white caterpillar (growing larger over a couple weeks). I have not seen a cocoon to know what, if anything, it becomes.