Looks as if it'll flower soon. Then you'll know.

Amsonia illustris?

Thank you, both!

floral, I noticed the tiny flower buds and was actually disappointed…. I was hoping for something showy. :) It’s cold and raining again so it will be a while before the buds open.

Jay, based on my image searches, I’m not familiar with that plant. I guess we’ll wait and know more once it blooms.

Most Caryophyllaceae have opposite foliage.

I thought Amsonia illustris ranged into the northeast, but it's a southeastern species. The leaves on this plant are much narrower than Amsonia tabernaemontana, but there is Amsonia tabernaemontana var salicifolia that has leaves like the featured plant. The flower buds still have a ways to go, and they enlarge quickly right before opening, and they put on a nice show.

Is an unusually slender Hesperus matronalis a ludicrous idea?

Peren.all, it reminded me of silene too, but I don’t think that’s it.

Jay, my searches on Amsonia didn’t turn up anything that was familiar to me.

floral, I’ve grown Dames Rocket for years, and it’s definitely not that.

I fear that whatever it is will disappoint us all. :)

I really doubt Silene because of the leaf arrangement.

We're stuck in a long run of cold and rainy days, so I'm not even bothering to go out there right now. lol! I'll be back if I have anything interesting to show. :)

Me too. So chilly and rainy for quite a while now after some gloriously warm weather. It will be warmer starting tomorrow. I hope you get the warm up!

Phlox barbatus - Sweet William???

The whiskery flower buds would be showing on Sweet Williams that far developed. And, being Caryophyllaceae, they'd have opposite foliage.

There are serrations that were hard to see, that's why I ruled out Vernonia. It's more likely to be Vernonia noveborasensis? The leaves are sessile. Amsonia leaves have petioles.

It doesn’t feel like it will warm up any time soon, and for weeks the official weather forecasts have been far too optomistic. lol! And I can say that it’s definitely not sweet william — I also grow that.

A loose dog appeared in the yard, so I had to attend to him. Since I was out there I snapped some current photos….

and I found some dame’s rocket in bloom to compare. I clearly see serration on the DR leaves but not at all on my unknown plant.

Jay, I had to look up Vernonia noveborasensis and I’ve never seen that plant before. Looking at more images, I think that it is a potential match to my unknown plant! what amazes me is how large this clump of plant is, given that columbine grew in that spot for the last several years.

eta: I don’t think that my mystery plant is tall enough to be Vernonia noveborasensis — I read that it’s 6-8’.

It's dense growth makes me suspect V. novebarasensis because I grow it. The 2 other most common ironweeds around Chicago are missurica and fascicularis which have one main stem that branches out higher up. Gigantea is likewise mainly a single stem.

My V. noveborasensis is extremely vigorous. Last year I gave my clump the Chelsea chop at least 5 times and it still ended up blooming profusely at 4 ft. tall.

It's also a Monarch Butterfly magnet.

I have a few plants of Fragrant False Indigo, Amorpha nana, growing next to my ironweed clump. I chop my noveborasensis back so my Amorpha plants can get sun, because the ironweed is such a huge beast, but it multiplies, by the clump simply enlarging, and it doesnt throw out creeping rhizomes in all directions.

I would post pics of my ironweed, but I cant post pics on gw now, and they dont have someone to contact for help. I have a couple plants that are mysteries but I cant get them ID'd without posting pics.

Ironweed leaves have minute prickles along their margins. What agastache species is yours? Foeniculum?My Lavender Wild Hyssup doesn't do very well in full sun. The ironweed is a keeper. Isnt it cool when beautiful plants show up in your garden, out of nowhere?

Jay, I originally received the seed in a trade: Agastache rugosa ’Honey Bee Blue’. It pops up occasionally wherever the seeds have spread and I love it. Great scent, bees love it, and it’s a nice filler in bouquets. :)

Can you PM me with the images? I checked and see an image icon in their messenger system, so maybe that will work.

Getting closer to blooming now:

OK. Here's my latest ludicrous guess. Campanula persicifolia.

C. persicifolia is possible. The basal leaves would be spatulate?

Yes, thank you, I’m convinced it’s C. persicifolia! I thought the leaves were too long initially, but as the stem grows and the flower buds form, it looks more and more like it. I’ll post photos when it blooms. :)

Funnily enough that was my very first thought but I didn't have the courage of my convictions. The growth seemed a bit denser than plants I'm used to. I've never seen any Amsonia so I couldn't compare. Do let us see when it blooms. The suspense ....!

I am so curious also. I grow C. persicifolia and have never seen such full top growth. Mine have basal growth and slender stems with very small short leaves. Yes, the suspense....!

The reason it looked so familiar to me is that I have C. persicifolia popping up around my yard every now and then -- both blue and white flowers. But these plants have such lush growth and long leaves that I didn't think that was it. lol! It hasn't bloomed yet but I will post pics when it does.

Tada! they finally started opening yesterday and are the palest blue flowers I have ever seen on C. persicifolia. :)

Thank you for the update! At least it is a desirable and as usual kudos to floral.

Bingo! Thanks for the update.