Creeping Jenny blooms. This is why I love my weeds.

June 12 update: Deptford Pink (Dianthus armeria)

I feel pretty sure that this is it. And deer don't like it according to one website that says;
"The foliage of members of the Pink family tends to be high in saponins and unattractive to mammalian herbivores."

Cranesbill (Geranium endressii)

3/1/11 update: Thanks to Patricia Newport for the ID.

10/10/10: White boneset or thoroughwort. I'm letting it bloom but I won't let it grow next yr. Takes up too much real estate in my veggie garden.

Forget-me-not (Myosotis sylvatica).

I think Michelle and Theora are right: this is a forget-me-not. And I also think I have a vague memory of planting some seeds for this last year. They look so weedy coming up that I'm sure I've yanked up a bunch of them before they could bloom. If they survive the deer, they'll be keepers.

???

Sowthistle (Sonchus arvensis). [5/24/10 update]

Here's a picture from last year. I'm letting them spread. They're weedy but are also pretty, in a modest, plain-jane way. And I STILL don't know what they are.

Could be something I planted & forgot about. I wonder what it is? [8-13: Andrea says maybe Lobelia inflata. I'll look for flowers to be sure.]

Virginia bluebells (Mertensia virginica).

Near the C & O Canal off River Road in Bethesda.

Bluets or Houstonia caerulea.

Lesser celandine (not marsh marigold).

Ranunculus ficaria (not Caltha palustris). Also called fig buttercup.
Thanks to theora for the information.

Weeds in Italy versus weeds in Maryland. The ones with little white flowers look the same to me. (4/18/10: Hairy Bittercress)

Cardamine hirsuta.

Still a mystery. Looks like its name should have "cress" in it.

I think this is the same plant that I noticed last spring. Right here.
[4/19/10: Hairy bittercress (Cardamine hirsuta)]

??? It's kind of viney.

Yarrow? Yes, says Michelle. Achillea millefolium.

Could be lady's thumb, or Pennsylvania smartweed, or tufted knotweed. Anyone know for sure?

???

4/12/11: Turkish speedwell (thanks andrea, see comments). A delicate and hardy little groundcover.

Veronica liwanenis

See also September 23. Looks like, but isn't, rosemary. Even has the same tiny flowers. Has great fall color. [8-13: might be bog-rosemary per Andrea]

Jerusalem artichoke?

Most people, including me, wouldn't call these weeds. But they come up every year in the park next door and I've never been sure what they are. Deer don't eat them so I'd like to borrow a few plants for my yard in the hope they'll spread.

???

Spotted in my friend Shannon's front yard.

Yes, nutsedge. Specifically yellow nutsedge.

Cyperus esculentus.

It looks like wild rosemary but is there such a plant? [8-13: Andrea says Andromeda polifolia or bog-rosemary so we're going with that for now.]

??? Shepherd's purse maybe?

??? (10/6: could this be nutsedge???)

12/26/09 update: Aporn says this is an obedient plant.

Physostegia virginiana.

Sowthistle (Sonchus arvensis). [5/24/10 update]

???

???? Boneset maybe?

And this is ...?? (9/18: Possibly white wood aster.)

Eurybia divaricata.
This is what I'm calling it until someone corrects me.