Western hemlock – Tsuga heterophylla

hemlock branch showing needles at different lengths

At a Glance

  • Family: Pinaceae
  • Plant type: large conifer tree
  • Distribution: native to the Pacific Coast and Cascades and Coastal Ranges from northern California to Alaska and eastward in northern Idaho and Montana
  • Habitat: dry to wet sites, most commonly growing on decaying wood, climax species (shade tolerant regeneration) most abundant in mature forests
  • Height: 200 feet tall (60m)
  • Reproduction: Female cones are small (1-inch) seed, oblong, purple-green when young, light brown when mature. Male cones are small and yellow, less than 1/4 of an inch (3 to 4 mm) in length.
  • Leaves: evergreen needles short, blunt, widely and irregularly spaced, of unequal length, producing feathery sprays, top of needles yellow-green underside that twist at the base to appear 2-ranked
  • Generation: perennial
  • Notable features: Washington State’s official state tree, the drooping top leader is a diagnostic feature

Restoration and Conservation

  • Canopy evergreen conifer trees like Western hemlock reduce erosion by intercepting rainfall in the rainy winter months and spreading out the timing of its impact on the soil surface
  • The shorter life span (500 years) compared to many other conifers in our mature forests means this species provides more frequent dead wood (e.g., snags, nurse logs) contributing to our forest ecosystems.
  • Host to many butterflies and moths

Ethnobotany/Commercial Use

  • High tannin content, commonly used as a tanning, cleansing, and pigment solution
  • Quileute used the bark for tanning hide and making spruce-root baskets watertight
  • Some Coast Salish would use the bark to create a red dye used on mountain goat wool and basket materials. Also used as a hair remover and facial cosmetics
  • Various tribes would use the bark to dye fishing nets brown- rendering it invisible to fish
  • The bark was great for carving into various utensils and tools, branches made for great bedding.
  • Haida made huge feasting bowls from the bent trunks
  • Fine twigs of young branches used as a “trap” for herring spawn
  • The pitch, outer, and inner bark could also be used medicinally

Resources

For questions regarding the EERC Native Plant Guided Tour, contact Sarah Verlinde-Azofeifa at severlin@uw.edu.