Coreopsis tripteris

I love the challenge of DYC, Damn yellow composites. Bring it on!😆

As it is the season for all these yellow flowers, it's important to take, and show photos of the flower face on, the bee's eye view, the back of the flower, the involucre, all the different types of leaves present on the plant, and a clear shot of the stem. Helianthus and Rudbeckia species, especially, are difficult to tell apart and that's why it's important to have all these different views.

Awesome! Thank you, thank you and I certainly WILL give you more challenges.

OK, how about this one? I thought I might be able to ID it myself, but half the websites just want to sell me seeds. None of the coreopsis exemplars I clicked on had pointy, sawtoothed leaves. Also diagnostic might be the reddish stems. These are on a chest-high plant whose seeds I had harvested last fall in D.C. from a meadow next to a trail (without paying attention to its foliage). The plant in the meadow was only about waist-high. I'm guessing the difference might be due to plenty of

water in my yard and less sunlight.

cpacker, the green leaves look different to me. I believe there are tall sunflowers and certainly plenty of prairie dock blooming but I don't think mine are either of those. I think I'll go back tomorrow to look for these again and get better photos. Thank you for responding. I'll let you know what I find.

I think we're both waiting for Jay 6a to return...

There certainly are tall sunflowers, but I don't think this is the one you have...

How about Bidens aristosa ?

http://jimbotany.com/Monastery_Plants/Bidens%20aristosa.htm

http://www.missouriplants.com/Bidens_aristosa_page.html

Yes, mine has got to be Bidens aristosa. I now learn that it's good for pollinators. That was my objective, though these were just an afterthought when I harvested about five times as much goldenrod seed. Exactly two goldenrod plants grew. Not sure what happened there.

cpacker, next time start your own thread and give your location please.

Grindelia lanceolata

Helianthus tuberosus and Rudbeckia triloba

Helianthus anuus, Wild form

Verbesina alternifolia

Helianthus mollis

Rudbeckia laciniata

Verbesina

I'm not sure if these photos are much better but here are a few more:

Parker, the involucre is a perfect match for Coreopsis tripteris. Another good way to identify it is the odd pinnate leaves, with 3 or 5 leaflets, and it gets tall, about 8'.

Thank you, Jay. I will take you up on your dare to "bring it on" and post several more DYCs for you to identify!