This list looks vastly different if one is simply considering butterflies. However, if you want birds, you need caterpillars. If you add moths and their foodplants, it helps at all levels. I'd still like to hear about non-woody plants for butterflies though. I'm always looking to add.

Powerhouse plants: University of Delaware researchers Doug Tallamy and Desiree Narango identify key native plants that support shrinking number of insects, stabilize food webs
https://www.udel.edu/udaily/20...

Am watching this youtube presentation by Doug Tallamy

In this free Audubon Florida webinar titled "A Guide to Restore the Little Things that Run the Wild," presenter, Doug Tallamy focuses focus on birds and native plants. He is the author of Bringing Nature Home and Nature's Best Hope
https://www.youtube.com/watch?...

UrbanWild said:This list looks vastly different if one is simply considering butterflies. However, if you want birds, you need caterpillars. If you add moths and their foodplants, it helps at all levels. I'd still like to hear about non-woody plants for butterflies though. I'm always looking to add.

Powerhouse plants: University of Delaware researchers Doug Tallamy and Desiree Narango identify key native plants that support shrinking number of insects, stabilize food webs
https://www.udel.edu/udaily/20...

Go Bluehens!

With regard to keystone plants, goldenrod is the all time winner, supporting hundreds of species of moths, butterflies, bees, and wasps. Think of it as the "oak" of herbaceous plants. Doug Tallamy has a section in his book, "nature's best hope" just for goldenrod. You may also consider other plants for the following seasons:

Spring: violets; Columbine; bulbs, crocus (excellent for early emergence of bees)
Summer: joe Pye, milkweed, bergamot, liatris, (this list is long)
Fall: goldenrod, asters

P.s. thanks for the acorns! 🙂 But I never would have been made aware of the crucial role of goldenrod had it not been for Prof. Tallamy. 🙂

Zinnias, Lantana & Coleus blooms are the most popular @ my house. And blue curls, which is just starting to bloom. Hard to have just a little of that though. LOTS of seeds. It is definitely hardy here too.
Forked Blue Curls (Trichostema dichotomum)

There is an enormous list of nectar plants here:
https://garden.org/thread/go/1...

Since they can bloom at such different times, I think it works best to have as much variety as I can find/get.

If you wonder if butterflies visit a plant, do an internet search for name of plant and the word butterfly. If you see pics of butterflies on it, you don't need to find it on a list somewhere, you've seen it. Butterflies do have lists of known host plants, which is usually a significantly different and abbreviated list vs. a list of acceptable nectar plants.

The same can be done if hoping to attract hummingbirds. The pics tell the story.

Blooming goldenrod is insanely mobbed with all sizes of bugs.
I'll be reading that initial link to see what else it lists.