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- Cupressaceae
- Thuja
- Thuja occidentalis
Thuja occidentalis — northern white-cedar
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Facts
Northern white-cedar is widespread in moist and wet forests of the north, but becoming increasingly rare and local in Connecticut and Massachusetts (where it is considered vulnerable to extinction). It is one of New England's longest-lived trees, lasting 200-300 years, hence its common name arbor-vitae (tree of life). Because the wood is resinous and resists decay, northern white cedar is a popular choice for constructing log cabins and manufacturing shingles. The wood is very light and insulates well. Its fragrant foliage and pyramidal growth form (in open habitats) make it much sought-after for gardens, and many cultivars exist. The aromatic sap is rich in vitamin C. Scientists study the rings of these exceptionally long-lived trees to understand year-to-year changes in past climates.
Habitat
Cliffs, balds, or ledges, fens, forests, ridges or ledges, shores of rivers or lakes, swamps, woodlands
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Growth form
- the plant is a tree
- Leaf form
- the leaves are scale-like
- Leaf cross-section
- the needle-like leaves are flattened (can't be rolled between the fingers)
- Leaf arrangement
- there are two needle-like leaves per node
- Seed cone form
- the seed cone is longer than wide, with woody scales attached at the base
- Leaf clustering
- the needle-like leaves are single, with two per node
- Seed cone shape
- the seed cone is ellipsoid (oval, tapering to rounded ends)
- Leaves overlapping
- the needle-like leaves are tightly overlapping so that they hide the twig surface
-
Fruits or seeds
- Seed cone base
- NA
- Seed cone bracts
- NA
- Seed cone form
- the seed cone is longer than wide, with woody scales attached at the base
- Seed cone scales
- NA
- Seed cone shape
- the seed cone is ellipsoid (oval, tapering to rounded ends)
- Seed cone symmetry
- the seed cone is symmetrical
- Seed cone umbo position
- there is no raised portion on the seed cone scale
- Seed cone umbo spine
- NA
- Seed wings
- the seeds have wing-like projections
-
Growth form
- Growth form
- the plant is a tree
-
Leaves
- Leaf arrangement
- there are two needle-like leaves per node
- Leaf base
- NA
- Leaf clustering
- the needle-like leaves are single, with two per node
- Leaf cross-section
- the needle-like leaves are flattened (can't be rolled between the fingers)
- Leaf duration
- the needle-like leaves remain green all winter
- Leaf form
- the leaves are scale-like
- Leaf glands
- the needle-like leaves have glands on the underside
- Leaf stalks
- the needle-like leaves do not have a leaf stalk
- Leaf types
- there are two distinct types of needle-like leaves on the twig
- Leaves overlapping
- the needle-like leaves are tightly overlapping so that they hide the twig surface
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- cliffs, balds, or ledges
- fens
- forests
- ridges or ledges
- shores of rivers or lakes
- swamps
- woodlands
-
Stem, shoot, branch
- Bark resin blisters
- there are no resin blisters on the bark
- Branchlet thickness
- 1–2 mm
- Leaves on shoots
- the needle-like leaves do not grow in tight clusters on a short, knob-like shoot
- Twig bloom
- there is no bloom on the twig
- Twig hair type
- the twigs have few or no hairs on them
- Twig hairs
- the twig does not have hairs
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Connecticut
- rare (S-rank: S2), threatened (code: T)
- Maine
- widespread (S-rank: S5)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
From Flora Novae Angliae dichotomous key
1. Thuja occidentalis L. N│E
northern white-cedar. CT, MA, ME, NH, RI, VT; throughout most of northern New England, but becoming rare and local to the south. Shorelines, fens, swamps, and cliffs, also an occasional component of upland forests to the north.
Native to North America?
Yes and no (some introduced)
Sometimes confused with
- Chamaecyparis thyoides:
- branchlets terete or tetragonous, alternating pairs of leaves similar, and seed cones nearly spherical, with peltate scales (vs. T. occidentalis, with branchlets flat, alternating pairs of leaves dimorphic—those of the upper and lower rank flat, those of the lateral ranks folded, and seed cones ellipsoidal, with basifixed scales).