杨桐·海桐·拆桐文献考论

Textual Research on Yang Tong(杨桐,Adinandra millettii),Hai Tong(海桐,Pittosporum tobira) and Chai Tong(拆桐)

杨桐可以作为植物染料,寒食、清明前后以杨桐叶染饭是江南民俗。海桐是著名的观叶植物,明代将海桐、山矾混同;而在宋代,山矾另有所指。"海桐皮"其实是刺桐皮,与海桐无关。臭梧桐花期长、花序大,为著名园林花木。胡桐,即胡杨,出自西域,胡桐树脂有药用等价值。"拆桐"是后人断取柳永词而生造出来的,"拆桐花"就是泡桐花。

Yang Tong is a kind of raw material of plant dyestuff. For people who lived in south of Yangtze River, it is a tradition that they use the leaves of Yang Tong to dye the rice around the Cold Food Day and the Tomb-sweeping Day. Hai Tong is a famous foliage plant. In Ming dynasty, Hai Tong was often confused with Shan Gong （山矾, Symplocos sumuntia）. But in Song Dynasty, Shan Gong means the other plant. Actually, the so called bark of Hal Tong is the bark of Ci Tong （Erythrina variegata） , and has nothing to do with Hai Tong. Chou Wutong （Clerodendrum trichotomum） has a long florescence and a large inflorescence, which is one of the famous garden plants. Hutong, namely Huyang （Populus euphratica ）, came from western regions. The resin of Hutong has medicinal values. Chai Tong is fabricated from Liu Yong＇ s Ci, and the so called flower of Chai Tong is just the flower of Pao Tong （Paulownia）.