Ok. I went looking for some of the seed mixes in "plantable" cards and here's some I found from different vendors... #1 Mountain Garland, Siberian Wallflower, Shasta Daisy, Chinese Houses, Lance-leaved Coreopsis, Purple Coneflower, Spurred Snapdragon, Forget-Me-Not, Johnny-Jump-Up, Blue Pimpernel, Chinese Forget-me-not, European Columbine, Annual Candytuft, Sweet William, Foxglove, Annual Baby's Breath, Baby Blue Eyes and Corn Poppy. #2 Red Corn Poppy, Corn Poppy, Spurred Snapdragon, Catchfly, English Daisy, Showy Evening Primrose, Gold Yarrow, Roman Chamomile, Tussock Bellflower, Foxglove, Fringed Sagewort, White Yarrow, Red Yarrow, Monkeyflower and Creeping Thyme #3 Sweet William Pinks Dianthus barbatus Rocket Larkspur Delphinium ajacis Candytuft Iberis umbellata Baby Blue Eyes Nemophila menziesii Corn Poppy Papaver rhoeas Forget-Me-Not Myosotis sylvatica Wallflower Cheiranthus allionii Columbine Aquilegia caerulea/A. vulgaris Blue Flax Linum perenne lewisii Zinnia Zinnia elegans Lemon Mint Monarda citriodora Five Spot Nemophila maculata Catchfly silene armeria English Daisy bellis Perennis Sweet Alyssum lobularia maritima Spurred Snapdragon linaria maroccana Corn Poppy papaver rhoeas Black Eyed Susan rudbeckia hirta #4 Catchfly silene armeria English Daisy bellis Perennis Sweet Alyssum loblaria maritima Spurred Snapdragon linaria maroccana Corn Poppy papaver rhoes Black Eyed Susan rudbeckia hirta And so on. Google has more but these are some of the top hits. These lists may inspire other suggestions.... While your card could be of a different mix, I suspect that your plants are pretty common garden plants - that is what most of these mixes feature. And I think it is most likely one of the plants already suggested to you. Conditions and the youngness of the plant could make the leaves not appear like mature plant leaves - which you will find mostly when you search for images of the plant. Keep watching. I'm sure it will eventually tell you what it is! FataMorgana

^^^ Yes, those pics were taken just yesterday. Thanks to our global meltdown...it was 81° F then, mosquitoes are out again, and some plants are now leafing out again... For example, here is Sambucus canadensis elsewhere in the park (pic taken today), for comparison. So, I don't think the OP plant is Elderberry - which has long tails on its leaves and its young stems are less woody, as shown.

Yes, went back and found one blooming...definitely an aster! Any idea what type, exactly? Looks similar to Roadside Aster (Aster exilis), but it has wider leaves? And I also actually did relocate the old Prairie Phlox nearby, too!

This ~6" volunteer was found growing in a hellstrip. It has leaves about ~3" long with toothed edges. Any idea what it is...maybe Heartleaf Peppervine (Ampelopsis cordata)?