FLORA OF THE VALLEY : ACACIA

Because of its spectacular color and tolerance of dry climates, the acacia is common throughout the San Fernando Valley as an ornament in landscapes. But the soil-binding qualities of this evergreen--an Australian native--also serve to protect hillsides, mountain slopes and banks during heavy rains.

The rounded, billowy trees have been planted along freeways to act as screens against dust and the glare of headlights.

Acacias were first introduced to California in the 1850s. Although 20 species grace Valley landscapes, the Sydney golden wattle ( Acacia longifolia) , pictured in full bloom on Tunney Avenue in Northridge, is the most common.

Bright golden-yellow flowers in loose 2 1/2-inch spikes fill the Sydney golden wattle’s branches. The clusters are accentuated by slender, green leaves three to six inches long. They have a sweet fragrance that attracts birds.

The trees offer the perfect shade-tree solution to summer’s blistering heat, and can be grown easily from both seeds and cuttings.

Acacias differ widely in foliage and growth patterns. Some species have divided, feathery leaves, whereas others have flattened leaf stalks.

But all acacias have a short, 20- to 30-year life span. These fast-maturing trees are known to grow 20 feet high and 20 feet wide within three years.

Flowers usually bloom January through April.