Blue Vervain

Karen P. I think you are correct .
Compare to my spotting,
http://www.projectnoah.org/spottings/133...

Ahh... I think it may be Blue Vervain. I can't see the leaves too well in your pic. I'm assuming they are finely saw-toothed. But the description seems to suit:
"Note the branching, pencil-like spikes of 5-petaled flowers that bloom a few at a time, advancing toward the pointed tip. Stem grooved, 4- sided.

Dangit...I've seen these before.... can't bring up the name!...... rats rats rats... going to get my guidebook! This'll bug me till I find it!