山楂有上百種，生長於北半球。它的學名 Crataegus 拉丁文意即「力量」（strength），用以描述此木的硬度。它的花果葉皆可食，果常被做於果醬或釀酒。
作者：Nadiatalent , Public Domain
山楂所含的植物化學成份有單寧、生物類黃酮、酚酸、聚合前花青素。聚合前花青素，有同劑量維他命C20倍的抗氧化能力。
研究發現，山楂中的WS122物質，能夠引發一氧化氮所促成的血管放鬆和擴張。血管一擴張，血壓就下降。
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