White Alder

Alnus rhombifolia

A 50-80 ft. tall, single-stemmed,  deciduous tree that lives to be only about 100 years old. It is scattered to locally frequent along water courses, especially in mountain canyons in riparian forest and woodland; mountain foothills and Santa Ana Mountains (Roberts). They are often found as a thicket of small trees along a permanent stream. During floods, great stands of these trees may be washed away and are rapidly replaced by dense masses of seedlings.  The root nodules contain the nitrogen-fixing bacteria Frankenia (Clarke). White alder is used for firewood, as lumber, and as an ornamental.  Native Americans extracted red dye from the bark and used it for their baskets, and made a perspiration-inducing tea from it, used in their sweat houses. Its greatest value lies in the ability to protect watersheds and provide wildlife habitat. 

The thin bark is ashy gray with mottled whitish-gray patches.  The trunk is marked by dark, drooping, eyebrow-like scars formed where the lower lateral branches have fallen off (Clarke). Fruits occur in cone-like catkins which appear in the fall and flower in early spring before the leaves appear. 

Flocks of pine siskins frequently feed on the maturing 'cones'.  Sapsuckers feed on boring beetles and other insects on these trees, and enjoy the oozing sap from the holes they make in the trunk (Clarke). Flowering: January-March.

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