any of various plants of the genus Sempervivum native to the Old World,especially S. tectorum,having a persistent,basal rosette of fleshy leaves and a branching cluster of pinkish or purplish flowers

• 任一种长生草属植物，产于欧洲大陆，尤指屋顶长生草，叶子肥厚，常绿，底部呈圆花型，开有带分支的淡粉色或淡紫色花序