Scientific Name: Alnus rubra
Common Name: red alder
Family Name: Betulaceae
Origin: B.C. west of Cascades, U.S. - northwest, U.S. - southwest
Hardiness Zone: Zone 5: (-29 to -23 °C)
Plant Type: Tree - deciduous
Mature Size: 22 - 30m x 7 - 10m (height x width)
Habit: Stiffly upright
Form: Oval - vertical
Texture: Medium
Landscape Uses: Erosion control, Native planting, Tall background, Wetland - bogs, Woodland margin
Exposure: Full sun
Soil or Media: Acidic, Humus rich, Well-drained
Leaves: Simple, Alternate, Soft flexible, Heavily veined, Pinnate venation, Glabrous, Lustrous, Elliptic, Ovate, Double serrate
Flowers: Catkin (ament), Yellow, Mar-Apr-Aug
Fruit: Samara, Brown, Aug-Sep-Oct, (Persistent)
Key ID Features:
Leaves alternate, ovate-elliptic, 7-13cm long x 5-8cm wide, 8-15 major veins on each side of midrib about parallel; margins double serrate and rolled under; poor fall colour (leaves often fall off green); male catkins 8-15cm long, hanging in small clusters at stem tips; female catkins woody, barrel shaped 1.2-2.4cm long x 1-1.3cm wide, arise at various angles from twigs. Winter ID: new twigs three sided, becoming rounded; buds stalked, oblong, 10-14mm long, red; leaf scars raised, half-round to triangular with 3 bundle scars; persistent woody cone catkins and/ or immature male or female catkins.