Fill a saucepan with 1 inch of water, and insert a steamer basket. Place the green beans into the steamer basket, and sprinkle with oregano, celery salt, and onion powder. Cover and bring to a boil over high heat. Steam for 5 minutes, then remove beans from steamer basket, and place into a large bowl.
Gently fold in the blackberries, allowing the heat from the green beans to pull out their juices. Season to taste with salt and pepper, and serve.
