Picea mariana
A slow-growing boreal conifer, official tree of Newfoundland and Labrador.
Picea mariana, commonly known as black spruce, is a North American species of spruce tree in the pine family. It is widespread across Canada, found in all 10 provinces and all 3 territories, and is the official tree of Newfoundland and Labrador, where it is the most abundant tree. Its range extends into northern parts of the United States, including Alaska, the Great Lakes region, and the upper Northeast, and it is a frequent part of the taiga or boreal forest biome.
- Scientific name
- Picea mariana
- Family
- Pine (Pinaceae)
- Native range
- Canada (all provinces and territories), northern United States (Alaska, Great Lakes, upper Northeast)
- Typical height
- 5–15 m (15–50 ft), occasionally to 30 m (98 ft)
- Typical trunk diameter
- 15–50 cm (6–20 in), occasionally to 60 cm (24 in)
- Cone size
- Smallest of all spruces, 1.5–4 cm (1/2–1+1/2 in) long
- Symbolism
- Provincial tree of Newfoundland and Labrador
Lore & Background
It is a pioneer that invades sphagnum mat in filled-lake bogs, often preceded slightly by tamarack. On drier sites following fires, black spruce can take over stands of faster-growing jack pine due to its ability to grow in partially shaded conditions. The spruce budworm causes defoliation that can kill trees if it occurs several years in a row, though black spruce is less susceptible than white spruce or balsam fir.
Reader's Guide
Black spruce is ecologically and economically significant across boreal North America. It is the most abundant tree in Newfoundland and Labrador and a key component of the taiga biome. Its timber, though of low value due to small tree size, is an important source of pulpwood in Canada and is increasingly used for cross-laminated timber, as well as for fast-food chopsticks. Along with red spruce, it has been used to make spruce gum and spruce beer. Numerous cultivars have been selected for gardens, including the dwarf form 'Nana', which has gained the Royal Horticultural Society's Award of Garden Merit. The tree's ability to tolerate nutrient-poor, acidic peatlands and its role in post-fire succession make it a vital species in boreal forest ecology. Its natural hybridization with other spruces and its distinctive wood properties—such as the large difference between heartwood and sapwood moisture content, easily distinguished in ultrasound images—add to its scientific interest. The frequent fire return interval perpetuates successional communities, with paper birch and quaking aspen invading burns before black spruce eventually dominates.
Did You Know?
- The Latin specific epithet mariana means 'of the Virgin Mary'.
- Black spruce cones are the smallest of all spruces, measuring 1.5–4 cm long.
- Tilted black spruce trees are colloquially called 'drunken trees' and are associated with thawing permafrost.
- Fast-food chopsticks are often made from black spruce.
Frequently Asked Questions
What is Picea mariana?
Black spruce is a slow-growing conifer in the pine family native to North America. It thrives in cold, acidic, often peaty soils and is a defining member of the boreal forest biome.
Where can you find Picea mariana in the wild?
It is present in all ten Canadian provinces and all three territories, making it one of the most widely distributed trees in Canada. Its range also extends into Alaska, the Great Lakes region, and the upper Northeastern United States.
How large does Picea mariana typically grow?
Most specimens reach 5 to 15 meters in height with trunk diameters of 15 to 50 cm, though exceptional individuals can approach 30 meters. It is generally a modest-sized spruce compared to many of its relatives.
What sets Picea mariana apart from other spruces?
Its cones are the smallest of any spruce species, measuring only 1.5 to 4 cm long. It also tends to be a slower grower and tolerates wetter, more nutrient-poor conditions than most of its conifer neighbors.
Why is Picea mariana considered important?
It is the official provincial tree of Newfoundland and Labrador, where it is the most abundant tree species. More broadly, it forms a critical component of the boreal forest ecosystem that blankets much of northern North America.
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