idiom · Chinese knotweed (Polygonum multiflorum), a species of herbaceous perennial vine native to central and southern China

这种何首乌的藤蔓爬满了整面墙。

noun · the dried root tuber of Polygonum multiflorum, widely used in traditional Chinese medicine to nourish the liver and kidneys and to darken hair

中医认为服用何首乌可以延缓白发的生长。