Unfortunately, Teri, I agree with the poster who said it was Cassia (or Senna) corymbosa. This plant is native to Argentina. I had one years ago, and never found a single sulphur egg on it.
Interestingly, the most widely used cassias in my area are C. obtusifolia/sicklepod, a very common weed of roadsides and pastures, and C. bicapsularis/Christmas cassia. Neither of these are native. The only native cassias I know of in this area are C. fasciculata/partridge pea and another "ferny" leaf type that I think is C. nictitans. These are common roadside plants, but I've never found a caterpillar on them or the partridge peas I've grown specifically for them. I guess this is a case where non-natives have become so common that they've supplanted the natives in popularity with the local sulphurs. Surely, if there was no Christmas cassia or sicklepod, they'd go back to using the natives? I wonder!
Butterfly gardeners in Florida have reported that their sulphurs like C. alata/candlestick cassia, but they only laid eggs on mine once, before the favorites had leafed out much, and I never found any caterpillars. I don't know if the eggs were duds, or if there was something about the C. alata leaves that killed them? C. alata is very cold tender, also, so I don't grow that one anymore.
Sherry

In St. Louis, MO, Partridge Pea - an annual, and Senna marilandica - Wild Senna, a perennial both work as host plants.

Candlestick, Popcorn, and Christmas Cassia are all favorites here in Florida. There are others that are similiar to the Christmas Cassia that are used as well but I don't know the names of them. I know that the Partridge Pea is around here also and the small sulphurs use my Perennial Peanut groundcover also.

Both Cloudless Sulphur and Sleepy Oranges use my Senna bicapsularis, a non-native. I used to have Senna hebecarpa, which they also used. It is native to the US, but not Oklahoma. I know they also use Partridge Pea as well, and probably many other Sennas.

Susan

> something about the C. alata leaves that killed them?

Not about the leaves. Rather ants. They adore Senna (yes) alata, for its extrafloral nectar.

> in Florida.... similiar to the Christmas Cassia... I don't know the names

In S.E. US, all or practically all individuals and businesses that think that they
bought /were given /are selling Senna bicapsularis
instead bought /were given /are selling Senna pendula var. glabrata.
S. bicapsularis has name Christmas "Cassia"[sic].
Thus S. pendula var glabrata also has name Christmas "Cassia"[sic].