flowering plant buttonbush, button-willow or honey-bells cephalanthus occidentalis blooming in summer

america attractive beautiful bloom blooming blossom botanical botany bud butterfly buttonbush buttonwillow cephalanthus close closeup cluster common corolla cream delicate details flora floral flower flowering flowers fragrant garden gardening geometrical green honeybells inflorescence macro medicinal nature north occidentalis original ornamental petals plant shrub spherical summer tree unusual white