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White Alder

TREES

GENUS/SPECIES


Alnus rhombifolia

FAMILY


Betulaceae

SYNONYMS


Information not available

DISTRIBUTION


Western US

  • West central Washington southward to SW California
  • SW California northward to west central Nevada and west central Idaho
  • West central Idaho westward to west central Washington

Comments

White alder often forms a clump of small trees, but sometimes an individual tree may have a trunk with a diameter of 12 inches. This species is typically found in areas where there is a consistent supply of water, such as along streams. It ranges from sea level up to over 7000 feet, but its distribution is widely scattered within its range. The bark is smooth when the tree is young, but develops plates and ridges as it ages. The rather thick leaves are about 2 to 4 inches in length and are widest near the center, helping to give this tree its specific name, and each leaf has fine teeth at the edges. The male catkins release their wind-blown pollen during the winter months. The seeds are borne in small cones a half-inch in length or less. This species is sometimes cultivated as an ornamental.