Greetings,


I have attached two images of the plant that decided to grow in my
backyard.


I would like to request your help in identifying this plant.


The leaves of the plant are really big, one of the picture has a quarter
coin to provide some relative size. Stalks look somewhat like celery
stalks, but with small bristles or thorns. Its more than 2 feet tall and
still growing.


One theory I have about origin of the plant is it came from homemade
vermicompost I use. The area was tilled and vemicompost applied before
plant appeared. Initially it looked like pumpkin vine, but now it looks
totally different and is not a vine but more like a bush.


Main interest in identification is ensure that it's not invasive species
and make sure that it's not poisonous to humans and cats in the backyard.