Alnus incana subsp. rugosa Speckled Alder
General
A Nitrogen-fixing, multiple-stem, small tree or large shrub that prefers wet to moist soils. Provides excellent wildlife cover. Will grow in a wide variety of locations, including stream edges and swamps, and is fairly adaptable. Good for bank stabilization.
Plant Description
Separate male and female flowers are produced on the same plant (monoecious), starting in early spring. Drooping male catkins are slender, cylindrical, to 2 inches long, female flowers are round catkins (1/2 inch) and develop by the fall into small seed-bearing cones. Cones may persist through the winter. Leaves are toothed and pointed at the tip, (as opposed to European alder/Alnus glutinosa which is notched at the leaf tip). “Speckled” refers to the lenticels on the bark.
Height (ft)
15-25
Spread (ft)
10-20
Soil moisture
Moist to Wet
Soil types
Fine to Medium
Wetland indicator
FACW
Shade tolerance
Tolerant, Full Sun to Part Shade
Bloom color
Yellow
Bloom period
Early Spring
Fall conspicuous
No
Anaerobic tolerance
High
Drought tolerance
Low
Salinity tolerance
Low
Self Pollinating?
Yes
Range
Frequently found along the edges of water bodies from mid-Canada south to Virginia and west along the Great Lakes.
![Kartesz, J.T. 2024. Floristic Synthesis of North America, Version 1.0. Biota of North America Program (BONAP) [website http://bonap.org/]](https://newp.com/wp-content/uploads/2024/10/Alnus-incana-1024x625.png "Alnus incana")
Additional Information
According to BRIT - Native American Ethnobotany Database, this species has been used by many Native American tribes medicinally and in dye making. The inner bark has been used to make yellow dye and the boiled bark has been used to make orange/reddish dye. A decoction/infusion of the inner bark used to restore the brown color of moccasins. An infusion of the bark has been used to treat anemia, and a treatment for sore eyes. An infusion of the twigs used for backaches and sprains.
