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Thuja occidentalis

Thuja from Greek thyia (a fragrant wood), possibly from thyein (to sacrifice, burn incense) — referring to the aromatic wood. occidentalis from Latin occidentalis (western), meaning 'of the west' from the European perspective, distinguishing it from Asian species.

Eastern White Cedar

Cupressaceae

Distinguishing Features

  • Scale-like overlapping leaves flattened into fan-like sprays; bright green above, paler below with faint white stomatal markings
  • Crushed foliage has a distinctive strong aromatic scent (thujaplicin compounds)
  • Cones small (8–14 mm), oblong, brown, with 8–10 thin scales; cones persist on branchlets
  • Bark fibrous, grey to reddish-brown, shredding in long vertical strips
  • Trunk often buttressed at base; can be multi-stemmed in exposed sites
  • Slow-growing, long-lived; some cliff-face specimens exceed 1,000 years old
  • Evergreen conifer, typically 10–20 m in open conditions, often shorter and shrubby on cliffs

Habitat

Highly variable: swamps, bogs, fens, and poorly drained lowlands (most common habitat in Ontario); also rocky limestone cliffs and alvars. Tolerates waterlogged and calcium-rich soils. Cold-hardy.

Bloom Period

April to May (wind-pollinated; inconspicuous pollen and seed cones)

Native Range

Eastern North America from Nova Scotia to Manitoba, south to Tennessee; the dominant tree of many Ontario swamps and the Niagara Escarpment cliff communities

Notes

Called 'Arborvitae' (tree of life) in cultivation — Jacques Cartier's crew were saved from scurvy by Indigenous peoples using a tea from the foliage, rich in Vitamin C. Thuja wood is naturally rot-resistant. The oldest known trees in eastern North America (1,000+ years) cling to Niagara Escarpment cliff faces. Provides critical winter cover and food for deer, which heavily browse it. Widely used in hedging.

Tags

Biogeography
native
Life Form
treeconifer
Phenology
perennialevergreen
Habitat
wetland
Ethnobotany
medicinal
Ecology
wildlife-value
Misc
long-lived