Alder Tree

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The Whole Tree!


The Bark!


The Leaf!

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The Fruit!


Angiosperm, Dicot, deciduous


An average Alder tree grows to a height of 30 to 40 feet and 6 feet in circumference. The tallest ones can grow up to 70 or 80 feet. They grow very fast relative to other trees, many up to half a meter every year for the first 30 or 40 years. Specific species include the Black Alder, which can grow up to 90 feet, the Red Alder, which can grow up to more than 100 feet, and the Italian Alder, which can grow up to 80 feet.

Identifying Features:

All alder trees have cone-shaped female flowers which kind of look like small pine cones. These cones are visible throughout the entire year, even in the winter when other floweres are dead. The leaves of the trees are oval shaped and can grow quite large, almost as big as your hand.


In general, Alder trees prefer very wet and humid conditions(near streams and ponds). Alder trees are located throughout the Northern temperate zone. They are also located in South America from the Andes all the way down to Chile. The most eminent species is the black alder, which orginated in Europe but have spread out throughout the world. The tallest species, the red alder, which can reach a height of over 100 feet, are native to the west coast of North America.


The leaves start growing during April and fall in November. The fruit starts developing any time from October to December and usually ripen in late December. The catkins, or the elongated male flowers (about 2-7 cm long), appear in late February to mid-March. The strobiles, or the mini-pinecone-like female structures (about 1-2 cm long), persist for most of the entire year.

Water/Sun Requirements:

The italian alder, or Alnus Cordata, can survive in relatively dry conditions. Only the most persistent arid environments will wither their leaves. For the white alder, full sunlight is would be best for the tree but it can survive in partial or even full shade as well, but the black alder requires sunlight to grow. The white alder requires a medium to high water supply.

Special Adaptations:

The roots of the alder tree can fix nitrogen themselves. This way, the alder tree can grow in a variety of difference soils.

Other Info:

  • The tree can be harmful if grown too close to buildings because the roots can extend very far, but if given enough room and water, it is a very good tree to have because it emits a semi-sweet fragrance.
  • The wood of the tree is brown and is very porous and course - it is often used to make clogs.
  • The wood of the tree was once used as charcoal in gunpowder.
  • The bark and leaves of the tree contain high amounts of tannin, a substance found in tea and many wines.
  • The leaves were used in folk medicine to cure colds.

Reference Sources/Links:

Created by Jerry L. 2007