Alternate‑leaf Dogwood
Scientific Name: Cornus alternifolia
Common Names: Pagoda dogwood, Green osier dogwood
Family: Cornaceae
Native Range: Eastern North America (southern Canada to eastern United States)
Typical: Small understory tree or large shrub
Maximum recorded heights: ~15 m
Trunk Diameter
Average: 15–25 cm
Maximum: ~40 cm
Growth Rate: Medium
Lifespan:
Typical Lifespan: 50–80 years
Record Age: ~120 years (estimated)
Seed Maturity (age at which it starts producing viable seeds): ~5–8 years
Reproductive Cycle (how often it produces seeds..e.g., every 2–3 years): Annually once mature
Soil Preferences (preferred soil type..e.g., sandy loam, well‑drained): Moist, well‑drained loam; tolerant of sandy or rocky soils
Water Needs (moisture requirements..e.g., drought tolerance): Moderate moisture; low drought tolerance
Canadian & USDA Hardiness Zones: Canada zone 3–7; USDA zones 3–7
Bark:
Young trees: Smooth, greenish to reddish‑brown
Mature Trees: Gray‑brown, becoming shallowly ridged
Needles (or Leaves)
Number per bundle: N/A
Length: 6–12 cm
Shape: Ovate to elliptic, pointed tip
Colour: Medium green above, paler underside
Cones: N/A
Seeds:
Size: ~6–8 mm (contained in berry‑like drupe)
Dispersal: Birds and small mammals
Growth Form
Shape: Horizontally layered branching (“pagoda” form)
Height: Typically 6–10 m
Reproductive Features
Flowers: Small, creamy white, clustered
Male: Perfect flowers (both sexes present)
Female: Perfect flowers
Pollination: Insects (primarily bees and flies)
Seed Maturity: Late summer to early fall
Unique Features: Distinct alternate leaf arrangement (unusual among dogwoods); tiered branching habit
Fire Resistance:
Rating (low, medium, high): Low
Fire Regeneration: Resprouts from base if lightly damaged
Shade Tolerance: High (well adapted to understory conditions)
Strength Rating: Low (wood is soft and not load‑bearing)
Decay Resistance: Low to moderate
Pest/Disease Resistance: Susceptible to dogwood borer, leaf spot, canker, and powdery mildew
Climate Adaptability: Tolerates cold winters; sensitive to drought and extreme heat
Uses:
Timber (construction, furniture, etc): Not used structurally; occasionally for small wooden items
Non‑timber products (e.g., resin, wildlife habitats): Ornamental planting; wildlife food source
Ecological Role:
Importance for wildlife (e.g., food for squirrels, birds): Fruits eaten by birds, bears, and small mammals
Role in forest ecosystems (e.g., stabilizing soil, providing canopy): Understory diversity, shade structure, insect support
Cultural Significance:
Historical Use: Limited traditional use; valued ornamentally for form and flowers
Threats: (Current conservation concerns or invasive threats): Habitat loss, drought stress, increasing disease pressure
Sources / Citations
1: Ontario Ministry of Natural Resources and Forestry (species accounts)
2: USDA Forest Service – Silvics of North America
3: Flora of North America (Cornus alternifolia)
4: Dirr, M. Manual of Woody Landscape Plants
5: Canadian Forest Service publications
6: University extension dendrology resources