Common

Trees of Alaska

United States 

Department of 

Agriculture

Prepared by 

Forest Service

Alaska Region 

R10-MB-703 

March 2010
Western hemlock – Tsuga heterophylla

Needles

•	 Light- to medium-green on top, with two whitish parallel lines beneath, needles are unequal 

in length from 1/4 to 7/8 inch long;

•	 Blunt-tipped, soft, shiny, and flat, generally

growing from two sides of branch parallel to 

the ground.

Cones

•	 Brown, oval-shaped, 5/8 to 1 inch long;

•	 Thin, papery scales.

Bark

•	 Reddish-brown when young, turning graybrown;

•	 Scaly when young, becoming thick and furrowed with age.

Size at maturity and life span

•	 100 to 150 feet in height and 2 to 4 feet in 

diameter; 

•	 200 to 500 years.

Habitat and distribution

•	 Sea level to subalpine areas;

•	 Along Coast Range in central California to the 

Kenai Peninsula of Alaska.

Western hemlock – Tsuga heterophylla
Mountain hemlock – Tsuga mertensiana

Needles

•	 Dark green, white lines on both surfaces, moreor-less equal in length, 1/2 to 1 inch long;

•	 Soft and growing from all sides of the branch in 

a bottle brush pattern.

Cones

•	 Purplish when young, brown when mature;

•	 Cylindrical, 1 to 2-1/2 inches long;

•	 Thin, papery scales.

Bark

•	 Divided into narrow flattened ridges, becoming

thick and deeply furrowed with age;

•	 Gray when young, turning reddish brown with 

age.

Size at maturity and life span

•	 50 to 100 feet in height and 10 to 30 inches in 

diameter, can be prostrate in alpine;

•	 Slow-growing trees, size 18 to 20 inches in 

diameter at 180 – 260 years;

•	 400 to 500 years

Habitat and distribution

•	 Sea level to 3,500 feet elevation;

•	 From crest of the Sierra-Nevada in California to 

the Kenai Peninsula in Alaska.

Mountain hemlock – Tsuga mertensiana
Alaska yellow-cedar 

Cupressus nootkatensis

Needles

•	 Scalelike, overlapping, sharp pointed, 1/16 to 

1/8 inch long;

•	 Yellow-green to deep green;

•	 Top and bottom of branch sprays similar, without apparent white stomate markings.

Cones

•	 Spherical about 1/2 inch in diameter;

•	 Green, maturing to brown in 2 years;

•	 Made of 4-6 shield-shaped scales, sharp central point on each scale, scales do not overlap.

Bark

•	 Shredding, grayish brown.

Size at maturity and life span

•	 Slow-growing trees;

•	 40 to 100 feet tall, and 1 to 2 feet in diameter;

•	 Shrub-sized and contorted in bogs and at tree 

line;

•	 Lives up to 1,500 years.

Habitat and distribution

•	 Wetland and subalpine forests;

•	 Sea level to tree line;

•	 From Oregon north along coast through Prince 

William Sound, Alaska.

Alaska yellow-cedar – Cupressus nootkatensis
Western redcedar – Thuja plicata

Needles

•	 Scalelike shiny yellow-green. 1/16 to 1/8 inch 

long;

•	 Springy, fan-shaped sprays of branches, turning 

up at ends;

•	 Branch sprays flat and symmetrical, bottom

side with white stomate markings.

Cones

•	 Brown, oval-shaped, 1/2 inch long;

•	 Clustered near end of branches;

•	 Cone scales overlap, woody, and curve outward at maturity.

Bark

•	 Fibrous and stringy;

•	 Cinnamon-red when young, becoming gray 

with age.

Size at maturity and life span

•	 70 to 100 feet in height in Southeast Alaska 

(growing much taller in southern part of range) 

and 2 to 4 feet in diameter (occasionally reaching 6 feet);

•	 300 to 700 years (occasionally 1,000).

Habitat and distribution

•	 Coastal forests;

•	 Sea level to 500 feet in elevation;

•	 From northwestern California to Southeast 

Alaska just south of Frederick Sound.

Western redcedar – Thuja pilcata
Sitka Spruce – Picea sitchensis

Alaska’s state tree

Needles

•	 Dark blue-green, squarish, 5/8 to 1 inch long;

•	 Needles sharp, growing on all sides of branches from woody pegs, a character common to 

spruce.

Cones

•	 Light orange-brown, 2 to 3-1/2 inches long;

•	 Usually found in the top quarter of tree, hanging down from branches;

•	 Papery scales.

Bark

•	 Thin and smooth when young, developing 

scaly plates with age;

•	 Gray, becoming dark purplish brown with age.

Size at maturity and life span

•	 150 to 225 feet in height and 5 to 8 feet in 

diameter;

•	 Grows to larger size in southern part of its 

range;

•	 500 to 700 years.

Habitat and distribution

•	 Well-drained, upland and riparian forests;

•	 Sea level to tree line;

•	 From northern California, northwest along the 

coastline to the Alaska Peninsula.

Sitka Spruce – Picea sitchensis
White spruce – Picea glauca

Needles

•	 3/4 to 1 inch long, blue-green, four-angled 

with whitish lines on all sides;

•	 Rigid, pointed, but not sharp to the touch;

•	 Usually crowded on upper side of the branch.

Cones

•	 1-1/2 to 2-1/2 inches long, light brown;

•	 Narrowly oblong, nearly stalkless, hanging 

down;

•	 Scales thin and flexible with smooth margins.

Bark

•	 Thin, scaly to smooth;

•	 Gray-brown, with white inner bark.

Size at maturity and life span

•	 40 to 70 feet tall, 6 to 18 inches in diameter;

•	 Reaches 80 to 115 feet tall, 30 inches in diameter;

•	 Tree crown, narrow or spire-like;

•	 Can live an age of 250 to 300 years.

Habitat and distribution

•	 From sea level to tree line on a wide variety of 

habitats;

•	 Throughout southcentral and interior Alaska 

east through Canada to Atlantic Ocean, from 

the northern tree line south to the Great Lakes.

White spruce – Picea glauca

White spruce

hybridizes with

Sitka spruce where

their ranges

overlap, forming

Lutz spruce,

Picea xlutzii.

It shows

characteristics

intermediate

between the two

parent trees.
Black spruce – Picea mariana

Needles

•	 1/2 inch long, light blue-green, four-angled 

with whitish lines on all sides;

•	 Blunt-pointed;

•	 Current year twigs with short red or brown 

hairs.

Cones

•	 1 inch long, rounded and dark;

•	 Scales rigid and brittle, margins rounded to 

toothed;

•	 Stay on for several years, hang on short stalks.

Bark

•	 Thin, gray to blackish, becoming flaky with

age;

•	 Inner bark is yellow.

Size at maturity and life span

•	 15 to 30 feet tall and 3 to 6 inches in diameter, 

larger in ideal situations;

•	 Can reach 250 years in age.

Habitat and distribution

•	 Wet and cold sites on flats or north-facing

slopes, also in bogs;

•	 Usually at lower elevations;

•	 Throughout southcentral and interior Alaska 

east through Canada to Alaska Ocean, from the 

northern tree line south to the Great Lakes.

Black spruce – Picea mariana
Shore pine – Pinus contorta var. contorta

Needles

•	 1 to 2-1/4 inches long;

•	 Two half-round needles in a bundle together 

making a cylinder when pressed together.

Cones

•	 Light brown, egg-shaped, 1-1/4 to 2 inches 

long;

•	 Woody, stiff prickles at the tip of each cone 

scale;

•	 Pointed backwards on branches.

Bark

•	 Dark brown to blackish;

•	 Resinous and scaly, becoming furrowed with 

age.

Size at maturity and life span

•	 Shrub-sized and contorted in bogs;

•	 Often a scrubby tree, 20 to 40 feet tall and 8 to 

12 inches in diameter;

•	 To 75 feet tall and 18 to 32 inches in diameter 

on well-drained, sunny sites;

•	 Lives 200 to 600 years.

Habitat and distribution

•	 Abundant in and adjacent to bogs;

•	 Sea level to subalpine;

•	 From northern California to Yakutat, Alaska.

Shore pine – Pinus contorta var. contorta

© Mary Stensvold
Tamarack – Larix laricina

Needles

•	 Deciduous, soft, flexible, 1 inch long;

•	 In clusters of 10 to 20 on short spur branches;

•	 Blue-green needles turn golden yellow and are 

shed in the fall.

Cones

•	 1/2 inch long, dark brown;

•	 With about 20 rounded, finely toothed scales;

•	 Held upright on short stalks from horizontal 

twigs.

Bark

•	 Young trees with dark gray, smooth, thin;

•	 With age becomes reddish brown, scaly, exposing darker inner layer.

Size at maturity and life span

•	 30 to 60 feet tall, 4 to 16 inches in diameter;

•	 100 to 200 years.

Habitat and distribution

•	 Bogs, moist places, and along river drainages;

•	 From the northern slopes of the Alaska Range 

to the southern slopes of the Brooks Range, 

east across Canada to Atlantic Ocean, from the 

northern tree line south to the Great Lakes.

Tamarack – Larix laricina
Paper birch – Betula neoalaskana (formerly B. papyrifera var. humilis)

Leaves

•	 1-1/2 to 3 inches long, 1 to 2 inches wide;

•	 Broadly oval with long-pointed tip;

•	 Margins coarsely double-toothed;

•	 Yellow-green, paler yellowish-green underneath;

•	 Twigs with dense covering of resin dots.

Fruit

•	 Nutlets borne in short, greenish-brown, dry, 1 

to 1-1/4 inch-long catkins;

•	 Nutlets tiny, with wings broader than the body.

Bark

•	 Red-brown on young trunks;

•	 Lightens with age;

•	 Smooth, thin, paper-like and peeling.

Size at maturity 

•	 To 80 feet tall, 4 to 24 inches in diameter.

Habitat and distribution

•	 Common in a variety of habitats, often in 

mixed forests with black and white spruce;

•	 From interior Alaska across northern North 

America to the southwest side of Hudson Bay.

Paper birch – Betula neoalaskana

Kenai birch 

(Betula 

kenaica) is 

nearly identical 

to paper birch 

except for 

slightly smaller 

size, leaves, 

and fewer 

resin dots on 

twigs. This tree 

is endemic to 

Alaska.
Balsam poplar – Populus balsamifera 

subsp. balsamifera

Leaves

•	 3 to 6 inches long, 2 to 4 inches wide;

•	 Broad at base, narrowing to a point at the tip;

•	 Dark shiny green above, rust-colored underneath;

•	 Swelling leaf buds are sweetly aromatic in the 

spring.

•	 Fruit

•	 2-parted capsules on 6 inch-long catkins contain numerous tiny cottony seeds.

Bark

•	 Young stems greenish to reddish brown;

•	 With age becomes thick and deeply furrowed.

Size at maturity and life span

•	 80 to 100 feet tall, to 3 feet in diameter;

•	 100 to 200 years.

Habitat and distribution

•	 River valleys and flood plains, alluvial fans,

glacial outwash areas, lake shores;

•	 A shade-intolerant pioneer species;

•	 From interior Alaska across northern portions 

of North America.

Balsam poplar – Populus balsamifera subsp. balsamifera

Black cottonwood 

(Poplus balsamifera 

subsp. trichocarpa) 

is nearly identical to 

balsam poplar except 

leaves are whitish 

underneath 

and it grows 

in southcoastal Alaska. 

Hybridizes with 

balsam poplar 

where ranges 

overlap. This 

is the largest 

broadleaf tree in 

Alaska.
Quaking Aspen – Populus tremuloides

Leaves

•	 1 to 31/2 inches long;

•	 Nearly round, pointed at tip and rounded at 

base, edged with many small rounded teeth;

•	 Shiny green, pale underneath;

•	 Leaf stalks flat, allowing leaves to tremble in

the slightest breeze.

Fruit

•	 Capsules on 3 to 4 inch-long catkins;

•	 Capsules contain numerous tiny cottony seeds.

Bark

•	 Smooth, greenish white;

•	 Important wildlife food.

Size at maturity and life span

•	 20 to 40 feet tall, 3 to 12 inches in diameter;

•	 80 to 100 years average, 200 years maximum.

Habitat and distribution

•	 South-facing slopes and well drained benches;

•	 Propagates from root sprouting after disturbance;

•	 Throughout interior and southcentral Alaska, 

across Canada and south to New Mexico;

•	 Widest distribution of any native tree in North 

America.

Quaking Aspen – Populus tremuloides
Red alder – Alnus rubra

Leaves

•	 2-6 inches long;

•	 Elliptic to ovate, shallowly lobed with coarse, 

rounded teeth;

•	 Leaf margins rolled under;

•	 Dark green, minute rust-colored hairs underneath.

Fruit

•	 Look like tiny pine-cones;

•	 Seeds, tiny dry nutlets with two narrow wings.

Bark

•	 Thin, smooth, grayish;

•	 Often appearing white due to incrustation by 

pale, flat lichens.

Size at maturity and life span

•	 20 to 80 feet tall, 4 to 25 inches in diameter;

•	 60 to 90 years;

•	 Rapid growth when young, but short lived.

Habitat and distribution

•	 Along rivers, floodplains, open gravelly areas,

disturbed areas to 1,000 feet in elevation;

•	 Often quickly colonizes disturbed areas;

•	 Most common hardwood on the Pacific coastline;

•	 From mid-California to Yakutat, Alaska.

Red alder – Alnus rubra
Scouler willow – Salix scouleriana

Leaves

•	 2 to 5 inches long, and 1/2 to 1-1/2 inches 

wide;

•	 Wider above middle, short-pointed at tip, 

edges without teeth;

•	 Young leaves velvety hairy;

•	 Older leaves dark green, sparse white to rusty 

hair underneath;

•	 Crowded at ends of twigs.

Fruit

•	 Seed capsules long, slender, gray-wooly.

•	 Bark

•	 Smooth gray, becoming dark brown, divided 

into broad flat ridges.

Size at maturity 

•	 Usually about 15 feet tall, 4 inches in diameter;

•	 Can grow to be 50 to 60 feet tall, 16 to 20 

inches in diameter.

Habitat and distribution

•	 Colonizes burned-over areas, thrives away 

from water;

•	 Forms thickets, often found along forest edges;

•	 A fast-growing, short-lived pioneer;

•	 From interior Alaska east to Saskatchewan and 

south to New Mexico.

Scouler willow – Salix scouleriana
Alaska spans a vast array of ecosystems 

from open, wind-swept tundra bordering 

the Artic Ocean, and Bering Sea through 

expansive boreal forests of the Interior to

impressive temperate rain forests along the Pacific

Coast.

Tree composition changes with the prevailing 

climate across the state. In the Interior, principal 

species include white spruce, birch, and quaking 

aspen on uplands, black spruce and tamarack 

in forested wetlands, and balsam poplar within 

floodplains. Willows are abundant in the Interior

as well, however most do not reach tree size.

The coastal temperate rain forests of southcentral 

and southeastern Alaska are comprised mainly 

of western hemlock, and Sitka spruce. Mountain 

hemlock, Alaska yellow-cedar, western redcedar, 

and shore pine are most often encountered where 

soils are more poorly drained. Deciduous trees 

are uncommon in the temperate rain forests of 

Alaska, and are represented mainly by red 

alder and black cottonwood.

This brochure was produced by the Alaska 

Region Ecology and Botany Programs.

Copyright illustrations by 

Bruce Lyndon Cunningham 

180 County Road 8201 

Nacogdoches, Texas 75964 

936-569-6965 - 936-462-0672 cell 

www.forester-artist.com 

brucelc@suddenlink.net 

Publisher & Illustrator of: Gymnosperms of the 

United States and Canada 

ISBN -978-0-934115-03-2 Softcover 

ISBN -978-0-934115-05-6 Hardcover 

Illustrations are not to scale.

The Alaska Region of the USDA Forest Service is an 

equal opportunity provider and employer. To file a complaint

of discrimination, call (202) 720-5964.

Pr ni ted on recycled paper