The creamy-white inflorescences of Bottlebrush Buckeye bloom in early Summer, are about a foot long, open from bottom to top, and have the general appearance of a bristly brush used to clean test tubes, beakers, flasks, or bottles in a science lab (hence the common name). The showy portions of the "small flowers" (parviflora) are the thin petals and extended stamens, together comprising the bulk of each tall inflorescence.