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Acacia melanoxylon

BLACKWOOD ACACIA

One of the largest of San Francisco’s street trees (to 40 feet in height, and much higher under ideal conditions), blackwood acacia is also one of the most common. It was planted heavily throughout the city in the 1960s and 1970s—so many large, mature specimens are now found citywide. The tree is evergreen, with dark brown bark and dense gray-green “leaves” 3–5 inches long, though they actually are not leaves but enlarged leaf stalks called phyllodes. (Botanists believe that phyllodes are a moisture-preserving adaptation to a dry climate.) In February and March, the tree produces an abundance of globular, pale yellow flowers that put out a great deal of pollen.

LOCATION: 1 Northwood Dr./Montecito Ave. in Westwood Park; also at 740 Masonic Ave./Hayes St.

Blackwood acacia is well adapted to San Francisco’s coastal climate and will grow (rapidly) almost anywhere on city streets, as it is not afraid of sidewalks. In fact, just the opposite is true: this tree’s aggressive roots will crack and lift sidewalks, which helps explain why in recent years it has been planted less frequently. Nevertheless, this is a good choice where a large, fast-growing tree is desired.