Which of the following is known as the Smoketree?

The Smoketree is known scientifically as Cotinus coggygria. This plant is characterized by its unique, airy clusters of flowers that produce a smoky appearance, especially notable in late summer when the feathery flower plumes develop. The foliage can vary in color, with some varieties showcasing vibrant autumn hues that enhance its ornamental value in gardens and landscapes.

Each of the other plants listed in the options serves different roles and has distinctive features—Cornus kousa, for example, is known as the Kousa dogwood, appreciated for its beautiful flowering and fruit; Chamaecyparis obtusa, commonly referred to as Hinoki cypress, is valued for its attractive foliage and texture; while Chionanthus retusus, or the Chinese fringetree, is prized for its fragrant spring flowers. However, none of these alternatives possess the hallmark features that define Cotinus coggygria as the Smoketree.