Buttonbush Cephalanthus occidentalis is a cold hardy wetland shrub that is excellent for supporting wildlife and an attractive ornamental plant with distinctive white flowers. Tolerant of flooding, this is a good shrub for a wet spot in the landscape, and can handle most soil types. Buttonbush provides habitat and food for many different types of birds, including mallard ducks and other waterfowl. The flowers attract butterflies, and are a good source of nectar for honey bees.