Cornus alternifolia, commonly known as Pagoda Dogwood, Alternate-leaf Dogwood, or Green Osier, is a species of flowering plant in the dogwood family Cornaceae. It is native to eastern North America, from Newfoundland west to Manitoba and Minnesota, and south to northern Florida and Mississippi. It is distinguished from other dogwood species by its alternate leaf arrangement, a trait reflected in its scientific name.
Description
Cornus alternifolia is a deciduous shrub or small tree, typically growing 5–9 meters (15–30 feet) tall, though it can occasionally reach up to 12 meters (40 feet). Its most distinctive feature is its horizontal, tiered branching pattern, which gives it the common name "Pagoda Dogwood."- Leaves: The leaves are simple, ovate to elliptic, 5–13 cm (2–5 inches) long, with an acuminate tip and an entire margin. They are dark green above and paler beneath, with prominent parallel veins. Unlike most other dogwood species, which have opposite leaves, Cornus alternifolia has an alternate leaf arrangement along the stem, though they often appear clustered at the ends of twigs. Fall foliage is typically a attractive reddish-purple.
- Flowers: Small, fragrant, creamy white flowers are produced in flattened, terminal cymes (flower clusters) 5–10 cm (2–4 inches) wide in late spring to early summer (May to June). Each flower has four small petals.
- Fruit: The fruit are small, round drupes, 6–8 mm (0.25–0.33 inches) in diameter, which ripen from green to red, then to dark blue-black in late summer to early fall (August to September). They are borne on bright red pedicels (stems).
- Bark: Young stems are smooth and reddish-brown, becoming gray-brown and slightly furrowed with age.
Taxonomy and Etymology
- Family: Cornaceae (Dogwood family)
- Genus: Cornus
- Species: C. alternifolia The genus name Cornus is from the Latin word "cornu," meaning "horn," likely referring to the hardness of the wood of some dogwood species. The specific epithet alternifolia is derived from the Latin words "alternus" (alternate) and "folium" (leaf), in reference to its characteristic alternate leaf arrangement.
Distribution and Habitat
Pagoda dogwood is found throughout the eastern half of North America, ranging from eastern Canada (Newfoundland, Quebec, Ontario, Manitoba) south through the eastern United States to northern Florida and west to Minnesota and Mississippi. It typically grows as an understory tree in moist woodlands, forest edges, stream banks, ravines, and along roadsides. It thrives in rich, well-drained, acidic to neutral soils and prefers partial shade but can tolerate full sun in cooler climates if adequate moisture is available.Ecology
Cornus alternifolia plays an important ecological role. The flowers are a source of nectar and pollen for various insects, including bees and flies. The ripe, blue-black fruits are a significant food source for numerous bird species, including American robins, thrushes, vireos, warblers, and cedar waxwings, as well as small mammals like squirrels, chipmunks, and foxes, and larger wildlife such as bears. The tiered branching structure can also provide shelter for birds and other small animals.Cultivation and Uses
Pagoda dogwood is widely planted as an ornamental tree in gardens, parks, and landscapes due to its distinctive architectural branching, attractive white flowers, colorful fruit, and appealing fall foliage. It is hardy in USDA plant hardiness zones 3-7 (sometimes 8).When cultivated, it prefers partial shade, moist, well-drained soil rich in organic matter. While generally resilient, it can be susceptible to some common dogwood diseases and pests, such as leaf spot, cankers, and dogwood borer, though often less severely than Cornus florida. Its wood is not commercially significant due to its small size and often irregular growth habit.