How to Switch from Smoking to Vaping Catalpa Tree Branches Pods Leaves Stock Photo 2586961485 Shutterstock Is Northern catalpa Safe for Children? Came across this tree in Hudson, WI that looked like it had giant green beans growing off of it, looked it up and it's called a Northern Catalpa often known as a " Vaping: How E cigs Work (Infographic) Live Science No these aren't giant tree green beans, but instead the seed pod of the northern catalpa. These bean like pods can grow to be 20" long and contain numerous 1" long seeds. #haverfordcollegearboretum #