Poison Ivy - Early StagesA poison ivy plant starts from a single seed. The seed spouts and produces two basal leaves (the two large leaves in the photo below.) Notice the two tiny leaves starting in the center of the plant. This seedling is approximately 3/4 to 1 inch wide.
I took the above photo at work. There's this amazing tree that is entirely covered in poison ivy and it makes hundreds of seedlings each year. I showed the photo to a woman I work with and she said, "Aww... it's cute!" It actually kind of is cute when it's little. Too bad it becomes such a pain in the butt later.
Within a week, the two center leaves start to grow:
Now it's starting to look like something resembling poison ivy. Depending on sun, rain, soil conditions, and other factors, this is about 3 weeks after it spouts.
Notice that the lowest two sets of leaves are directly opposite the stem from each other. Poison ivy leaves are always arranged on the stem alternately, not opposite. This is one of the criteria that can be used with certainty to identify poison ivy. However, when the plant is very young like this, the leaves are opposite. This is the only time you will see this on poison ivy. Read more about alternate and opposite leaf patterns.
Birds love poison ivy berries and suffer no ill effects whatsoever from eating them. Within the berries are seeds, which pass through the digestive track of the birds unharmed. The birds eat the berries, fly someplace else (like your yard) and poop. Pretty soon you'll have baby poison ivy plants!
These are immature poison ivy berries. When they mature, they will turn white.