The Tong tree 桐花 flowers from mid-April through mid-May in northwest Taiwan, usually right after the acacias finish their yellow flowering. About 90% of Taiwan's Tung trees are "wood oil trees" (木油樹) (Aleurites Montana (Lour.) Wils.), also called "thousand-year-old Tung" (千年桐), introduced from southern China circa 1915. New Garden City celebrates a Tung Blossom and Firefly Festival every Spring. Tung became an economic crop when Japan occupied Taiwan. Its seed oil was used for waterproof coating and its timber for matches, toothpicks and clogs.