A Lathyrus of some sort would be my opinion. Flower too wide for Vicia, except for Vicia lathyroides, of course, but on that one the wing and standard or banner colors are reversed. Where are you located?

Think it's some species of Phyllanthus; these plants are closely related to spurges.

Looks like Robinia pseudoacacia to me too. Where I grew up in Ohio it was an early succession tree in old fields and vacant lots; grows fast and doesn't live too long compared to, say, maples or oaks. On the plus side it has flowers in the spring that look like white wisteria and smell great; I've never understood why people didn't plant it just for the flowers.

^^^ 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.