black mustard

black-mustard的词性：
n.（名词）

1. A weedy, annual Eurasian plant (Brassica nigra) in the mustard family, having racemes of yellow flowers and pungent seeds formerly used to prepare the condiment mustard.
黑芥菜，幽芥：一种十字花科一年生蔓生植物（黑芥 芸苔属） 植物，长有黄色总状花序和尖形种子，以前用于配制调味芥末