Eastern Hemlock

(Tsuga canadensis)

Interesting Information About Plant: 

The Eastern Hemlock is a woody tree that can live for over 800 years. The bark contains tannins that were once used to process leather. The tree now is used at times for ornamental reasons and the wood is processed into pulp for the paper industry. In forests across North America, where the trees are located, wildlife uses it for protection, especially white-tailed deer that use it for bedding in the winter. The only pest that really affects the Eastern Hemlock is the woolly adelgid. The trees are also susceptible to root rot if located in an area where the ground can become very wet.

Common Name: Eastern Hemlock

Scientific Name:  Tsuga canadensis

Family Name (Scientific and Common):  Pinaceae

Continent of Origin: North America

Most Distinguishing Morphological Features of This Plant: Leaves are small, flat, green, and pointed. On the underside of the leaves are two parallel white stripes. These are caused by rows of stomata. The bark is brownish-grey.

Plant Growth Habit: Large Tree

Height at Maturity:  More than 10 Feet

Life Span:  Perennial

Seasonal Habit: Evergreen Perennial  

Growth Habitat: Partial Sun   & Shade

Manner of Culture: Native Species 

Thorns on Younger Stem? No

Cross Section of Younger Stem: Roundish

Stem (or Trunk) Diameter:  More Than The Diameter of a Coffee-Mug 

Produces Brownish Bark? No

Bark Peeling in Many Areas? Yes

Characteristics of Mature (Brownish) Bark:  Lines Go Up-Down & Bumpy 

Type of Leaf:  Needle-Like

Length of Leaf (or Leaflet):  Less than Length of a Credit Card 

Leaf Complexity:  Simple

Shape of Leaf:  Simple 

Edge of Leaf?  Smooth

Leaf Arrangement:  Alternate 

Leaf has Petiole? Yes

Patterns of Main-Veins:  Parallel

Leaf Hairiness: No Hairs

Color of Foliage in Summer:  Green

Change in Color of Foliage in October:  No Change

Flowering Season: Spring 

Flowers: Tightly Clustered 

Type of Flower:  Like a Pine Cone

Color of Flower: Yellow

Shape of Individual Flower:  Bilaterally Symmetrical

Size of Individual Flower:  Smaller than a Quarter  

Sexuality: Male and Female on Same Plant

Size of Fruit: Smaller than a Quarter 

Fruit Fleshiness at Maturity?  Dry

Shape of Fruit: Spherical

Color of Fruit at Maturity: Brown or Dry

Fruit Desirable to Birds or Squirrels? No   

Unique Morphological Features of Plant: 

Is the Plant Poisonous: None of Plant

Pesty Plant (weedy, hard to control)? No

Common Name(s):  Eastern Hemlock, Canada Hemlock, Hemlock Spruce

Louisville Plants That Are Most Easily Confused With This One:  T. Caroliniana (Carolina hemlock) and the Yews

Page prepared by:

Jessica R. Corder

November 2005