紫露草属（学名：Tradescantia）是鸭跖草科下的一属，约有71个物种，原产地加拿大南部和阿根廷北部。它们是纤细的向上或攀爬植物，高度为30-60厘米，并且通常单独或成片发现在树木繁茂的区域。叶子长、薄、呈片状至披针形，3-45厘米长。

花有白色、粉红色或紫色，但最常见的是亮蓝色，有3个花瓣和6个黄色的雄蕊。它的汁液是粘稠而透明的。一些物种在清晨开花，当下午阳光照到它们时合上，但是在阴天可以一直开到晚上。和大部分美国和加拿大野花不一样的是，紫露草是单子叶植物，不是双子叶植物。

虽然有时被认为是杂草，紫露草种植在花圃的边界，并在容器中种植。

Tradescantia /ˌtrædᵻˈskæntiə/, the spiderworts, is a genus of 75 species of herbaceous perennial plants in the family Commelinaceae, native to the New World from southern Canada south to northern Argentina including the West Indies. They were introduced into Europe as ornamental plants in the seventeenth century and are now grown as such in many parts of the world. Subsequently some species have become naturalized in various regions of Europe, Asia, Africa, Australia and assorted oceanic islands.