Any of several herbs or shrubs of the genus Iva of eastern and central North America, often growing in salt marshes and having nodding, greenish flower heads with unisexual flowers.

• 沼泽地松：生长于北美洲东部和中部盐碱沼泽地带的一种蓍花属的草类或灌木。花冠下垂，稍带绿色，为雌雄异花植物