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Arizona Alder

Alnus oblongifolia

Photo © by Michael Plagens

Leaves of Arizona Alder growing along Sycamore Creek in the Pine Mountain Wilderness, Yavapai Co., Arizona. June 2009.

Photo © by Michael Plagens

Photographed along Pinto Creek in Gila Co., Arizona, about 8 km from its confluence with the Salt River/Lake Roosevelt.

LEAVES: Deciduous, toothed, simple leaves are alternate on the stem. Veining is prominent.

RANGE: In Arizona's sycamore woodlands this tree grows along the better-watered canyons mostly at the higher elevations.

TREE: A medium-sized tree with smooth gray bark on younger trees and becoming darker and fissured on older trees. Boles generally straight. The roots host the nitrogen-fixing actinomycete, Frankia.
Arizona Alder catkins
FLOWERS: The small flowers are set in pendulat spikes known as catkins. Female catkins are much shorter and more compact than the male. Male flowers open in spring and are shed soon after releasing pollen, but the female catkins remain with developing seeds.

FRUIT: Overlapping papery scales of the catkins give the appearance of a small cone. Shown at right are immature female catkins containing developing seeds.


Betulaceae -- Birch Family

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Sycamore Canyons
The Flora of Arizona's Sycamore Canyons


Copyright Michael J. Plagens, 1999-2010