The pagoda dogwood, known by the scientific name Cornus alternifolia, is a species of ornamental tree indigenous to North America — specifically Canada and the northeastern area of the United States. Rarely, the tree appears in the southern United States, although it is considered imperiled or endangered in the states of Mississippi and Florida. Closely related to flowering dogwood trees, the pagoda dogwood's most notable characteristics are layered horizontal branches and clustered leaf arrangements. Typically, this species grows up to 25 feet (7.62 m) but can reach as tall as 30 feet (9.14 m.)
Common names include pagoda dogwood, pigeonberry, or alternating-leaf dogwood. Names, including the scientific name, alternifolia, stem from various attributes of the tree. For example, the name pigeonberry stems from passenger pigeons selecting the late summer to early fall berries as a favorite food. Alternifolia references the tendency for leaves to alternate along each stem to form the characteristic whirl pattern. Similarly, the name alternating-leaf refers to growing patterns of the pagoda dogwood leaves.
Unlike common flowering dogwoods, a pagoda dogwood produces less ornate and fewer blossoms, although it maintains the traditional white to creamy white colors. As the season progresses, flowers give way to berries that progress from green to blue-black, with a brief period of redness in between. Most flowers and berry clusters appear at the ends of branches and shoots. Leaves also grow in clusters along the layered branches, often having a swirled appearance similar to a fan. Although green during the spring months, fall finds the leaves turning a deep red, almost purple, color.
In the wild, the most common placement of a pagoda dogwood is under taller trees with open canopies or on the periphery of wooded areas with a mix of several tree species. A popular ornamental tree, horticulturalists typically select areas with full sun to cultivate pagoda dogwoods in gardens or around buildings. While the tree will grow in partial to full shade, sun encourages maximum bloom during the spring months of April and May. Owing to the ornamental appearance of the layered branches, many growers will select a pagoda dogwood for its visual appeal even in winter months, when leaves are no longer present.
Diseases are a problem for pagoda dogwoods. Seemingly immune to common dogwood diseases such as anthracnose, the pagoda is susceptible to golden canker, twig blights, and other diseases. Full-shade environments can lessen the effects of some pathogens, although the tree will not reach its full potential. Moist, well-drained soil and protection from drought can do just as much to prevent disease as choosing the right planting site.