Bur Oak (Quercus macrocarpa)

Other Common Names: Mossycup oak, scrub oak


  • Deciduous tree, grows up to 30m, usually smaller in Manitoba.
  • Grey to brown bark, deeply furrowed when mature.
  • Twigs are hairy when young, becoming hairless. Older twigs often form raised ridges.
  • Leaves are simple, alternate, ovate, lobed, and 15-30 cm long, with fine hairs on underside.


  • Fruit is an acorn, 20-30 mm long, half covered with a cap. Dispersed by animals.
  • Monoecious (individual trees have both male and female flowers)
  • Male flowers are green/brown, on catkins, 10-15 cm long, at the tip of last years growth.
  • Female flowers have green scales, tinged with red, growing on the axils of new growth.
  • Flowers appear in spring, before the leaves, male flowers maturing before female flowers, limiting self-pollination.
  • Wind pollinated.
  • Can also reproduce by shoots.

Similar Species:

  • Bur oak is the only oak tree native to Manitoba. It’s wavy/lobed leaf margins distinguish it from all other trees in the area.

Ecological Role:

  • Fire-resistant
  • Acorns eaten by bears, squirrels, rabbits, deer, and many birds.
  • Deer, elk, moose and porcupine eat the leaves, twigs, and bark.


  • Acorns

Other Uses:

  • Wood is used for cabinetry, hardwood floors, and fenceposts.


  • “Oak” comes from Old English “ac,” which is derived from an ancient name for the oak tree. “Bur” refers to the prickly husk around the acorn.
  • “Macrocarpa” means “large-fruited,” from Latin “macro” meaning large, and Greek “karpos,” meaning “fruit.”


  • Commonly lives 200-300 years, can live up to 400.

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