Oh my gosh! thank you, you are completely right! i know this for a fact since i trimmed them back last night and developed a minor rash on my hand and arm. i read up on it and there were warnings all over the place! do you know if you're supposed to cut this plant down? i hope so, i thought it was overgrown and cut it way down. i don't think it had ever been cut down and all the snake like things were REALLY long and snake like on the ground, half of them were brown so i figured that's what they needed. anyone have these?

maybe Daisy Fleabane (Erigeron annuus)? Here is a link that might be useful: illinois wildflowers - erigon annus

Looks like Primrose Willow (Ludwigia) sp. Not in the Willow (Salicaceae) family.

The ground cover variety is invasive. The shrub form is not. I dug out all the ground cover I had, and last fall I put in a shrub form, and it is blooming well right now, with no spreading. In most plants there can be numerous varietals, that have totally different behaviors. (That can often be a real pain, in deciding what to plant or not. I take my Sunset National Gardening guide with me when I shop, so I can look stuff up, for the nitty gritty, before I buy it. It has its own zone system, which is better for marginal plants, also.)