Alnus incana ssp. rugosa (Speckled Alder)
- Images, plant synonyms, scientific classification, and wetland indicator status. Includes conservation status.
- http://plants.usda.gov/java/profile?symbol=ALINR

Alnus rugosa (Speckled Alder)
- Describes habitat and characteristics of fruit and leaf. Provides images.
- http://www.oplin.org/tree/fact%20pages/alder_speckled/alder_speckled.html

Alnus incana - Alnus rugosa (Speckled Alder)
- Taxonomy, physical description, distribution, habitat, fire ecology, and associated flora and fauna. With an image.
- http://www.rook.org/earl/bwca/nature/shrubs/alnusincana.html

Alnus rugosa (Speckled Alder)
- Provides facts on physical features and habitat. Includes image.
- http://www.borealforest.org/shrubs/shrub3.htm

Alnus rugosa
- Information on distribution and occurrence, value and use, characteristics, and fire ecology.
- http://www.fs.fed.us/database/feis/plants/tree/alnrug/