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An initiative of Earthwatch Institute

  1. 80 Leaves by Kevin Kim
  2. 244_english_oak_-_by_david_shand_acorns_and_leaves Acorns and leaves by David Shand
  3. 061_english_oak_-_by_jaap_cost_budde_flowers Flowers buds by Jaap Cost
  4. 112_english_oak_-_quercus_robur_-_by_maggie_wang 50% leaves by Maggie Wang
  5. 088_english_oak_-_by_peter_o_connor_flowers Full flowering by Peter O'Connor

English Oak

Quercus robur

Appearance

  • A deciduous tree.
  • Size: usually 12 – 20 m high when planted in parks and gardens but can reach about 40 m high in its natural environment. Its low, wide-spreading and rounded canopy is usually 10 – 18 m wide.
  • Its trunk is typically short, with ridged dark grey to black bark.
  • Leaves: dark green and oval to rectangular in shape with 3 – 7 rounded lobes on either side. They are 7.5 – 12.5 cm long and have a very short stem. They are pale blue-green underneath and turn tan to brown in autumn, before falling from the tree in late winter.
  • Flowers: tiny, green to pale yellow, hanging in slim, cylindrical clusters (known as catkins).
  • Fruit/seed: oval acorns, 2 – 2.5 cm long, grow singly or in clusters of 2 – 5 at the end of a 5 – 10 cm long stalk. A cap covers about one third of each acorn.

What to Observe

  • First fully open single flower
  • Full flowering (record all days)
  • End of flowering (when 95% of the flowers have faded)
  • First fully open leaf
  • Leaves open (record all days)
  • Seeds (acorns) dropped to the ground (record all days)
  • First leaf to change colour
  • Leaves changing colour (record all days)
  • First leaf to drop this year
  • 50% or more of leaves dropped (record all days)
  • No leaves (record all days) 

ClimateWatch Science Advisor

We expect plants to start shooting and flowering earlier in the year as a result of climate change warming the Earth. They may also start appearing in new areas, as warmer temperatures enable them to live in environments that were previously too cold for them.

When To Look

  • Most of the year!
  • Leaves and flowers appear in early spring
  • Acorns appear after flowering (usually in autumn)
  • Leaves change colour in autumn before falling in late winter 

Where To Look

  • Throughout Australia, but especially in south and eastern Australia because it can be sensitive to frost and humidity. 
  • It is not native to Australia but has often been planted here in urban parks, gardens and along roadsides.
  • Look in urban areas, particularly in parks, large public gardens and along streets.

English Oak Occurrence Map ALA

References

Australian Biological Resources Study 1989. Flora of Australia Volume 3. CSIRO Publishing / Australian Biological Resources Study.

Bean W J 1976. Trees and shrubs hardy in the British Isles 8th ed., volume 3, revised. John Murray, London.

Miller HA and Lamb SH 1985. Oaks of North America. Naturegraph Publishers Inc., California.

Rushforth K 1999. Trees of Britain and Europe. HarperCollins.

Walther G, Post E, Convey P, Menzel A, Parmesan C, Beebee TJC, Fromentin J, Hoegh-Guldberg O, and Bairlein F 2002. Ecological responses to recent climate change. Nature 416: 389–395.

Links

  1. Search Species

  1. What Else?

    White Oak (Quercus alba): It doesn’t have the earlike lobes at the base of its leaves, or the very short leaf stalks.

  1. Did You Know?

    It may take up to 30 years to bear its first acorns but it can live for more than 700 years!

    It is native to Europe, western Asia and northern Africa.

    Its wood has been an important source of timber in England for centuries, and was used to make sailing ships when Britain reigned the high seas.

    There are more than 500 species of oaks (genus Quercus).