Botanical Name: Quercus macrocarpa
Common Name: Bur Oak
Origin: North America
- Spring Spring
- Summer Summer
- Autumn Autumn
- Winter Winter
- Leaf Leaf
- Bark Bark
- Flower- Male Flower- Male
- Flower - Female Flower - Female
- Fruit - Immature Fruit - Immature
Notable Feature: The bur oak is a mighty sight to behold. A coarsely textured crown, wild and wooly acorns, and a massive trunk with rough and deeply furrowed bark combine to make one impressive tree.
Habit: A large, deciduous tree in the white oak family known for producing the largest acorns in North America. This outstanding, ornamental tree will reach 60 to 80 feet high and 60 to 80 feet wide. The branches of the crown are ascending to widely spreading and somewhat crooked; the trunk is tall and stout and up to 5 feet across.
Flower: Ornamentally insignificant yellowish green flowers in separate (monoecious) male and female catkins appear in spring as the leaves emerge. The male flowers are produced in drooping yellowish catkins about 2 to 5" long; female flowers are either solitary or clustered together in groups of 2 to 3. Overall, a female flower has the appearance of a tiny narrow cone.
Fruit: Oval acorns (1 to 2” long), with fringed, burry cups that extend to approximately 1/2 to 3/4 the acorn length. Acorns are an important source of food for wildlife. Heavy nut crops (masting) are borne only every few years.
Foliage: Simple, dark green, with lobed margins shaped like a bass fiddle; 4 to 12” long and half as wide, they are the largest of any oak.
Bark: Rough, deeply ridged and furrowed; dark gray/brown in color.
Interesting Fact: In the evolutionary strategy known as “masting”, the large seed crop overwhelms the ability of seed predators to eat all the acorns, thus ensuring survival of some seeds. The Bur Oak wood is of high quality and possesses significant drought tolerance by virtue of a long tap root.