The Trees of San Francisco. Michael Sullivan
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its close relative the Norfolk Island pine, the bunya-bunya has a distinctive silhouette. As with other members of the ancient Araucaria genus, the tree’s branches are spaced evenly along the trunk in whorls, giving the tree a symmetrical look. Bunya-bunyas are large trees, often reaching 80 feet, and mature trees develop a characteristic rounded crown. The glossy green leaves are lance shaped, sharply pointed, and spirally arranged on branches. The tree is native to the Bunya Mountains of Queensland in northeastern Australia.
Perhaps the most unusual feature of the bunya-bunya is its football-sized female cone, which looks something like a pineapple and can weigh 10–15 pounds (the record is held by a 17-pounder). The cones, which set every three years, are produced high in the tree’s canopy and can cause serious injury when they fall. Each cone produces 50–100 large edible seeds, or bunya nuts. The nuts were a food source for Queensland’s aborigines.
LOCATION: 201 Vicente St./Wawona St. in West Portal. This is one of the most spectacular trees in San Francisco, and a rare tree in the city. Also at 1818 California St./Franklin St. in Pacific Heights; a grove of five trees in the park at the corner of Hyde St. and Jefferson St. in Fisherman’s Wharf; and in front of Chez Panisse restaurant at 1517 Shattuck Ave. in Berkeley.
When the cones set, the aborigines put aside their tribal differences and feasted. They headed for the Bunya Mountains, where each tribe owned particular trees. (Visitors to Bunya Mountains National Park can still see the notches carved into the trees to facilitate climbing for the harvest.)
Bunya nuts, a delicacy in Australia, are still eaten today. They can be eaten raw or roasted, and the nuts’ flour can be used to make breads and cakes.
Don’t Do This!
INDULGE me as I rant about two of my gripes concerning trees in San Francisco. The city has its share of beautiful trees, but there are times when I walk down a street and cringe. If I could change only two things about what happens to trees in this city, these would be the two:
LAVENDER IN THE TREE BASIN. Most street trees in San Francisco are planted as young trees in 2-foot-square cuts in the sidewalk, and people have a natural desire to plant flowers or other plants in the basins. Anything planted there will compete with the young tree just getting established, but plants with woody stems—such as lavender, rosemary, and ivy—are especially bad. Mature trees are not affected much, but the aggressive roots of these plants can choke a young tree by competing for water and nutrients.
AGGRESSIVE PRUNING. Why are so many San Franciscans afraid to let their trees grow? Trees are topped, or aggressively pruned, for many reasons, chiefly to keep upper branches out of overhead wires and to protect views. But I suspect many tree owners think they are helping the tree by lopping off the ends of branches to reduce the tree’s height or size, or to make the tree bushier or denser. Some plants react well to being cut back hard in this way, but most trees are not among them. Take my advice: let your tree grow, and help create a mature canopy your neighbors will appreciate.
Melaleuca quinquenervia
CAJEPUT
Of the 200-plus varieties of Melaleuca in Australia, the cajeput is the one most commonly cultivated, so much so that Australian sources refer to it as the “quintessential” melaleuca. Called broad-leafed paperbark Down Under, this tree has gray-green, leathery, 2- to 4-inch oval leaves and grows quickly to 20–30 feet. The tree’s spongy white bark can easily be peeled off in sheets and is used as a lining for hanging baskets. The yellowish-white flowers bloom in clusters from June to August, but they are not as showy as those of the flaxleaf paperbark (Melaleuca linariifolia ), a close relative that is also popular in San Francisco. The cup-shaped 3/16 -inch seed capsules form in clusters 2–3 inches long, and they can persist on branches for a year or longer. Cajeputs are well adapted to San Francisco’s conditions, tolerating poor and even salty soil and strong winds.
LOCATION: North side of 16th St. at Wisconsin St. on Potrero Hill; also Bryant St. (east side) between 18th and Mariposa Sts. in the Mission
The tree was introduced into southern Florida in the early 1900s for swamp drying. Having no natural enemies, it spread aggressively, crowding out the native vegetation that is essential for supporting animal life. Now, the cajeput poses a serious environmental threat to the Everglades and other expanses of southern Florida, where it is growing explosively, turning the natural grassy wetlands into dense melaleuca thickets. Biological control is now offering hope, however. The U.S. Department of Agriculture is releasing several species of Australian snout beetles, which are specific to melaleuca and feed on its shoots, reducing the plant’s ability to reproduce.
Aesculus californica
CALIFORNIA BUCKEYE
LOCATION: 2694 McAllister St./Willard St. N. near the University of San Francisco campus; also at 124 Lower Terrace/Levant St. in the Upper Market neighborhood
This is one of the few trees in this book that is a true San Francisco native, existing within the current city limits before the arrival of Europeans. The California buckeye also is one of the state’s most beautiful native trees, growing to 20 feet in height on wind-protected sites in the dry slopes and canyons of the coastal range and Sierra foothills. The tree produces showy, long-lasting clusters of white flowers in May and June. One or two pear-shaped fruits form on each flower cluster, and inside each fruit’s leathery jacket is a seed with a shiny brown coat. The tree’s light green leaves are divided into five to seven leaflets, which drop in July (an adaptation to long, dry summers) unless summer water is provided.
American Indians crushed this tree’s poisonous seeds and added them to dammed-up streams to stupefy fish, making them easy to catch. (Today you may find California buckeyes near old Indian campgrounds.)
Perhaps because of its spreading form, the California buckeye is rarely planted as a street tree in San Francisco, due to narrow urban setbacks. You can view a large and spectacular specimen in a yard at 2694 McAllister Street, near the University of San Francisco campus. The tree was scheduled for removal in 1999 in connection with new construction on the lot, but after a neighborhood outcry, plans for the house were changed to build around, and preserve, the tree. As part of the settlement, the property owner signed a tree easement with Friends of the Urban Forest, protecting the tree from future removal—and making this the only tree in the city protected by a contract.
Schinus molle
CALIFORNIA PEPPER TREE
A mature California pepper arching over a backyard patio is a cliché of Sunset magazine’s California lifestyle. Cliché or not, the California pepper is one of the most beautiful trees available to San Francisco tree lovers. Mature peppers have wonderfully gnarled trunks, supporting rounded crowns of graceful, arching branches. The fernlike foliage is finely textured, with bright green leaves composed of many leaflets. California peppers have either male or female flowers; female flowers develop into drooping clusters of showy rose-colored peppercorn berries in the fall and winter. The seeds are sometimes sold as pink peppercorns, although in large quantities they can be toxic. (To avoid messy fruit drop, many city dwellers plant trees with male flowers only.) Like its relative the Brazilian pepper, this tree is related botanically