sitchensis – refers to Sitka (Russian derived from Sheet-ka in Tlingit language), Alaska, where the species was first documented for western science

Native range: West Coast of North America

Leaves:

• alternate
• simple
• entire margins or with glandular teeth
• broad, tapering from above the middle of the base
• 4–9 cm long
• upper side bright green and sparsely silky
• lower side satiny with short hairs pressed flat, especially on younger leaves
• rolled under at the base
• stalks yellowish, velvety
• 5–15 mm long
• stipules half-oval (look like small leaves), either fall early (slow-growing twigs) or retained through season (vigorous twigs)

Flowers:

• dioecious
• upright catkins
• bracts brown, hairy, to 2.4 mm long
• catkins appear before or with the leaves, on short leafy shoots
• males to 5 cm
• females to 8 cm

Fruit:

• small (1/4 inch), long-pointed, silky (hairy) capsules in oblong clusters
• each capsule contains numerous small fuzzy seeds

Other characteristics:

• shrub or small tree (1-8 m)
• branches dark brown to grey, sparsely hairy
• twigs densely velvety, brittle at base
• deciduous

Relevant info:

• source of natural precursor to aspirin, salicylic acid, found in leaves and bark
  • in 4th century B.C.E., Hippocrates gave willow leaves to women to chew as a pain reliever during childbirth
  • French and German scientists pursuing folklore concerning the healing powers of willow bark competed to isolate the active component of willow bark
  • in Munich in 1828 Buchner successfully isolated a tiny amount of salicin, which was the major salicylate in willow bark
  • the name salicylic acid (SA), from the Latin Salix, was given to this active ingredient by Raffaele Piria in 1838
  • during the 19th century SA and other salicylates were isolated from a variety of plants
  • first commercial production of synthetic SA began in Germany in 1874
  • Aspirin, a trade name for acetylsalicylic acid, was introduced by the Bayer Company in 1898 and rapidly became one of the world’s best-selling drugs
• phytoremediation – degrades trichloroethylene (TCE), a chlorinated organic solvent used to remove grease from metal parts that is common and widespread groundwater contaminant (see Miller, Khan & Doty (2011))
• named by August Gustav Heinrich von Bongard (1786–1839), a German botanist who worked at Saint Petersburg, Russia, and in 1833 documented this species, among others, new to Western science in Alaska (then under Russian control)
  • the plant was observed in the field in 1827 by Dr. Henry Mertens, naturalist on Russian exploration voyage who would have corresponded with von Bongard
  • Tsuga mertensiana is named after H. Mertens, who also documented it in the Sitka area

Ecology & Adaptations:

• native to Alaska to California, east to Idaho
• in Washington, chiefly west of the east base of the Cascades
• found in moist woods and streambanks, tidal swamps and marshes, coastal fog belts and headlands, sand dunes, springs, gravelly streambeds and deltas, glacial moraines, avalanche tracks, dry canyons, clearings and edges of forests
• lowlands to moderate elevations in the mountains
• 0–1800 m.
• pollination:
  • by both wind and insects
  • consistent with wind pollination are flowering before leafing, inflorescences reduced to catkins, male and female flowers located on separate individuals, and male plants releasing large quantities of pollen
  • floral nectar glands, erect, stiff and highly visible catkins are consistent with insect pollination
  • bees, flies, and beetles observed
  • genetic diversity in large, continuous, interbreeding population along waterways supports importance of insect pollination
• seed dispersal by wind and water aided by cottony down (hairs)
• vegetative regeneration/reproduction:
  • sprouting from root crowns or stem bases, and by rooting of stems
  • spreads via underground runners or by layering (bent or broken stems form adventitious roots if buried and kept moist)
  • detached stem fragments form adventitious roots if buried in moist soil (hence use of live stakes in restoration), as may occur when stem fragments are transported by floodwaters and deposited on fresh alluvium (though seedling establishment appears more common)
• herbivore/microbial defense:
  • tannins in leaves interfere with digestion of proteins
  • salicylates protect against microbial pathogens
  • hairs on younger leaves deter herbivory
  • glands at leaf margins produce resin that limits insect herbivory
• shade tolerant:
  • leaves in shade are larger and thinner than those in full sun, which maximizes light capture while minimizing investment in photosynthesizing structure
  • in PNW, species often forms tall shrub understory beneath taller trees such as black cottonwoods (Populus trichocarpa)
• wetland adapted:
  • vegetative reproduction decreases reliance on seed germination
  • responds to disturbance/damage during flooding or beaver activity with regeneration at root crowns or trunk bases
• wildlife:
  • ungulates (e.g., moose) browse on twigs and leaves
  • small mammals (such as beaver) browse branches and leaves
  • birds feed on catkins