Distant rumblings from city hall portend a boom on Treasure Island, the former Navy base on the brink of becoming San Francisco's newest residential neighborhood. This exercise of urban planning in the middle of the bay will be a closely watched experiment. Early drafts of the master plan have called for sustainable design and green building development, for example, including an open space and landscaping component that emphasizes the use of locally native plants.
No plant is native to Treasure Island -- this 400-acre landmass was built of quarried rock and bay-dredged landfill in the late 1930s. But the first seawalls for that project were raised from the northern shoals of Yerba Buena Island, the natural island now joined with man-made Treasure Island like a siamese twin. And the steep slopes of Yerba Buena Island, though radically altered by invasive weeds and the hand of man, still harbor remnants of the original native flora, a population from which the landscape planners may wish to draw their inspiration.
Consider the coast red elderberry (Sambucus racemosa var. racemosa), enthusiastic seeder of moist forest margins, a proven survivor even in the deepening shadows of eucalyptus and monterey pine. This robust deciduous shrub can reach tree-like heights of 15-20 feet, filling the middle space beneath a taller canopy with a cheerful bloom of frothy white blossoms from March through July. Just now the fruit has begun to form, dramatic clusters of scarlet berries adored by birds. After the leaves drop in late fall, the bare elderberry still holds interest for its branches, which have a large pith and are easily hollowed out. The Ohlone used these twigs for flutes, whistles, and clapper sticks (a drum alternative); indeed, the genus name Sambucus pays homage to the Greek sambuke, a musical instrument made from elder wood. Excellent as a specimen plant in the garden or as a focal point in an urban park, and a tasteful alternative to cotoneaster, the coast red elderberry should rank high on anybody's landscaping wish list.
