Which of the following is not a type of Viburnum?

The choice that is not a type of Viburnum is Ajuga reptans. Ajuga reptans, commonly known as bugleweed, is actually a different genus and belongs to the Lamiaceae family, which is entirely distinct from the Viburnum genus. This means it does not share the characteristics typical of Viburnum plants, such as their specific flowering structures and foliage.

In contrast, the other options presented are all recognized varieties of Viburnum. Viburnum carlesii, commonly known as Korean spice viburnum, is appreciated for its fragrant flowers. Viburnum plicatum, or Japanese snowball, is known for its layered, flat-topped flower clusters. Viburnum x bodnantense is a hybrid that is particularly valued for its winter-blooming capabilities. Each of these Viburnum species contributes unique attributes to garden design and landscaping, making them popular choices among horticulturists and gardeners.