Aspen Poplar (Populus tremuloides)

Aspen Poplar (Populus tremuloides)Also known as: trembling aspen


Bloom time: March – May

Additional photos:

General: Deciduous tree, up to 30 m tall. Trunk is smooth with light green or pale bark. Large trees can have black cracks in the bark at the base. Poplar trees are either male or female – only male trees are observed for PlantWatch.

Leaves & Twigs: Leaves are small (3-7 cm long), light to medium green in colour, and round-shaped with a small, sharp tip.

Flowers & Fruits:

  • Flowers are found in catkins, which look like soft caterpillars hanging from twigs; blooming is completed before leaves emerge.
  • Male flowers: Fuzzy catkins emerge in late winter, and lengthen in early spring to reveal red/pink pollen sacs. These release pollen into the air, and the catkin eventually dries up and falls off.
  • Female flowers: Catkins turn green and capsules form, to later release fluffy, white seeds.

Habitat: Aspen is common in both dry and moist woods, but cannot tolerate shade.

PlantWatch Pointers: Tag a male tree for observation

To Observe:

  • First bloom: when the catkins on the male tree first start shedding pollen (3-places).
  • Mid bloom: when 50% of the male catkins have lengthened and shed pollen.
  • Leafing: when the first leaves have emerged and unfulded completely (3-places).

Distribution Map:

This species is monitored in:

  • Alberta
  • British Culumbia
  • Manitoba
  • New Brunswick
  • Newfoundland and Labrador
  • Northwest Territories
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan
  • Yukon

This tree was named because of the way the leaves flutter or tremble in even a light breeze.