I got a nasty rash from the back bush wondering what this is and if it could be the culprit.

Welcome Smaddock. Do you have a photo? Where in the world are you?

Sorry, upload didn't work I am in Southern Ontario developed a rash similar to poison ivy/oak. Wondering if this is the plant. One is of the plant, has an odd leaf that has two indents on the top, and the other is of the flower, a little purple.

It looks like blue cohosh, Caulophyllum thalictroides. Funnily enough I was looking as some in woodlands here earlier today. According to some references it can cause contact dermatitis in some people.

Edited to add, where I saw it there was also a lot of poison ivy so if it's the same where you are then it might not necessarily have been the blue cohosh.

Database information says the leaves and seeds of Blue Cohosh (Caulophyllum thalictroides) are poisonous but mentions nothing about contact dermatitis. I too wonder if perhaps Poison Ivy (Toxicodendron radicans) might be growing amongst the Blue Cohosh or somewhere very close by?

Oh my ... where are my manners, I forgot to say

Here's one of the references, this one specifies the roots which you're not likely to contact by just walking by, other articles don't specify the offending plant part and just make a general comment about contact dermatitis.

http://www.ct.gov/caes/lib/cae...

Thank you for all of the great information! The plant is very close to blue cohosh when compared to the pictures. I will take a look during daylight to be sure and rule that one out. I will be back with more pictures of anything else I find. Thank you guys so much.