alnifolia – leaves like the genus Alnus (Latin), similar leaves to Alnus glutinosa

Native range: Northern and Southwestern North America

Leaves:

• alternate
• simple
• serrulate
• ~ovate or rounded
• leaves red in fall
• small deciduous stipules

Flowers:

• inflorescence — terminal raceme
• white
• 5 sepals, fused at base w/ small teeth
• 5 narrow petals
• 10–20 stamens
• 2–5 styles

Fruit:

• small, berry-like pome
• red ripens to black
• contains 4–10 dark brown seeds with leathery seed coats

Other characteristics:

• deciduous trees or shrubs to 30 ft.
• delicately branching

Relevant info:

• fruits ferment on the shrub, which birds like
• susceptible to rust
• varieties overlap in distribution
  • typical variety (A. alnifolia var. alnifolia) occurs from southern Alaska to southern Oregon, mostly east of the Cascades, and east to the Dakotas, Nebraska, and Colorado
  • A. alnifolia var. humptulipensis occurs on the western slope of the Cascades in BC and Washington
• given the number of varieties of this species, local or on-site sources should be used for restoration or revegetation projects in the PNW

Ecology & Adaptations:

• Alaska to California, east to the Dakotas and New Mexico
• occurring throughout Washington
• found in dry to moist open woods, canyons and hillsides, rocky shorelines, bluffs, talus slopes, meadows, thickets and forest edges
• in well-drained soils
• sea level to subalpine elevations.
• pollination – primarily self-pollinated but may be cross-pollinated via insects or wind
• seed dispersal:
  • aided by the consumption of fruit by fur and game mammals (such as black bear, beaver, hares), upland game birds, and many species of rodents and songbirds
  • leathery seed coat prevents seeds from being digested in animal guts, though digestive acids will soften the coat
• reproduces vegetatively:
  • from stolons and suckers (stems from roots), sprouting from the root crown, and by layering (branches root when they touch the ground)
  • underground portions of the plant include massive root crown, horizontal and vertical rhizomes, and an extensive root system
• fire dependent:
  • re-sprouts from root crown and/or rhizomes after fire
  • abundance increases after fire
  • only somewhat shade tolerant, so populations decline as canopy closes in the absence of fire
• response to herbivory and disturbance:
  • twigs and foliage browsed, especially in winter, by wild ungulates (e.g., deer, elk, mountain goats, bison), fur and game mammals (e.g. black bear, beaver, and hares)
  • responds to browsing and fire damage with increased twig production
  • spreads when canopy trees are killed by insect outbreaks
• herbivore defense:
  • new leaves and young twigs contain toxic levels of hydrogen cyanide (prussic acid, cyanogenic glycosides), which is toxic and potentially fatal to ruminants such as deer
  • higher levels of this toxin are present in leaves and twigs during bloom stage and then rapidly decline