"V" is for Veronicastrum
You know that you know her. Why can't you think of her name! Vanessa. Vicky. Something like that. Okay. Ask her "so how's work" or something that might give you a clue in their answer where you know her from, and from that, you'll probably retrieve her name. Until you do, it drives you batty.
I get the same way about plant names that I should know, but they won't give clues and there's nobody to ask, and so I thumb through Newscomb's Wildflower Guide; I pick the closest plant family or genus and start surfing in Google Images. I go back to Newcombs and without the plant in hand, it's just a wild guess.
I ran across this one last week near Floyd. I knew at one time I had identified it--probably the first year I was here, in 1997. There was a trace of a name; all I could come up with was "something with a V". I find I do that with people names to. I can think back to classes of students from years ago, see a face in my mind, and tell you "her last name started with a G." So somewhere in that pink pudding called the cerebral cortex there is a filing system that links alphabetized names to images of all sorts. And for me, this is an important thread of memory to follow in the direction of name retrieval.
The V-ness of this plant, I felt certain about. I mulled it around for two days, and finally found it by accident-- the image in Newcombes doesn't do justice to the plant, called Culver's Root. Veronicastrum virginianum. No wonder it had such a strong flavor of "V" every time I looked at this picture.
Also, in that same sandy field were several other uncommon plants, two I identified for the first time: Wild Senna and Meadow Sweet, both I guessed to genus and had to key to species; and * Fly Poison, a tall lily that I'd seen a few places before, but not many. And there is one more that I CANNOT identify and no alphabet clues at all. Maybe I'll post the image and see if any of you can help, but it will crush my little ego to have somebody tell me.
* Fly Poison has one of those botanical names that's fun to say, and sounds to me like an incantation, so be careful how you use it: Amianthium muscaetoxicum! Poof! You're a gerbil!