Place beans in colander; rinse well.
Snap off stem end from each bean.
Slice beans lengthwise on cutting board; set aside.
To prepare celery, trim stem ends and leaves from ribs.
Reserve leaves for garnish, if desired.
Slice celery thinly on the diagonal.
Bring 1 inch of water in 2 quart saucepan to a boil over high heat.
Add beans and celery.
Cover; reduce heat to medium-low.
Simmer 8 minutes or until beans are crisp-tender; drain.
Toss beans and celery with butter.
Transfer to warm serving dish.
Sprinkle with sunflower seeds.
Garnish, if desired.