Jewelweed is avery common weed that is know to greatly alleviate the affects of poinson ivy. This stuff grows all over the place, often in areas where poison ivy is found. I have tons of it in my yard and it is over waist high, has a lightish green color and the blossoms just as seen in this photo. If you cut it low on the stem and put the juice on the areas affected by poison ivy you should have quick relief, at least so they say. I've heard it from a few people who've said they themselves have felt the relief.