Cal Flora Photo
Alnus viridis ssp. sinuata Lam & DC
Sitka alder is a deciduous shrub or, rarely, a small tree. Plants are typically multi-stemmed and bushy, up to 10 or 15 feet tall, often forming dense thickets. Occasionally, plants may grow to 30 or 40 feet at lower elevations. Height growth generally decreases with increasing elevation. The resilient branches are seldom damaged by snow creep or avalanches, allowing dense thickets to form on steep slopes subject to these disturbances. On these sites the 3 to 6 inch diameter stems often point downhill and then bow strongly upwards. The bark is thin, smooth, and reddish brown or gray. The leaves are alternate, ovate, 0.8 to 2.5 inches long, shiny green, with doubly serrate margins. Sitka alder has a shallow root system. Male and female flowers occur on the same plant in catkins. The separate male and female catkins are in small clusters on the same twig. Clusters of three to six pistillate catkins are approximately 0.5 inch long, each with a long, 1 to 1.5 inch stalk.
Sitka alder is generally found at middle to high elevations in the mountains of northwestern North America. It is moderately shade tolerant, which allows it to survive under stands of lodgepole pine (Pinus contorta), Engleman spruce (Picea engelmannii), subalpine fir, grand fir (Abies grandis), western hemlock, mountain hemlock Scattered thickets of Sitka alder are normally located on cool moist sites, on north-facing slopes, or other shady aspects. It is a vigorous invader of talus slopes, avalanche chutes, seepage areas, and high elevation mountain swales, which often have an abundance of surface moisture. These sites are often subject to deep winter snow accumulations and recurrent avalanches. Although typically mentioned as a seral shrub of cool, moist, shady upland sites, it also occurs along cool mountain streams. Soils: Sitka alder is found on a wide variety of parent materials and soil textures. Sitka alder is mostly distributed above 3,000 feet. (Source)
Food Uses: The catkins may be eaten raw or cooked, but have a bitter flavor. The inner bark and young buds are edible.
Medicinal Uses: The bark is
astringent, emetic, haemostatic; and may be used for stomachache and as a tonic.
Kutenai used a bark decoction to regulate menstrual flow, and Blackfoot used one
to treat TB of the lymph glands. The bark is also used like Cascara (but milder)
for constipation, jaundice, and diarrhea but must be aged or it will cause
vomiting. The inner bark can be used as a poultice to treat wounds and skin
ulcers and reduce swelling. Fresh scraped bark juice relieves itching from a
rash, and a fresh infusion treats poison ivy. Alder root has a very high tannin
content and it was boiled and drunk as an astringent if there was blood in a
personís stool. A leaf decoction treats burns and inflamed wounds. In Lapland,
people were covered with bags of heated alder leaves to treat rheumatism. In
North America, sometimes people put fresh leaves of Sitka Alder in their shoes
to reduce swelling and cool aching feet. (Source)
Other Uses: Alder is also an important dye plant.
Value to Animals:
Sitka alder has little forage value for big game animals.. Plants are occasionally eaten by mule deer. Dense stands provide cover for wildlife. Grizzly bears often forage in these areas, eating mesic herbaceous plants as they green up in the spring and berries from shrubs in the summer and fall. Muskrats, beavers, cottontails, and snowshoe hares eat alder twigs and leaves. Beavers eat the bark of alders, and build dams and lodges with the stems. Alder seeds, buds, and catkins, are eaten by redpolls, siskins, goldfinches, chickadees, and grouse, and are an important winter food source. (Source)
Return to Alphabetical Listing