Uh oh, look who’s on the roof. It’s wall lettuce, Mycelis muralis, and it seems to be performing a haughty victory dance.
This plant with its distinctively lobed, arrowhead leaves is a member of the Asteraceae. It is native to most of temperate continental Europe, and is a weed in many other parts of the world, including the Pacific coast of North America. In can behave as an annual in disturbed sites, or, if given a chance, can grow as a biennial.
It has puny yellow flowers that produce fluffy little seeds that end up anywhere, including eavestroughs, and germinate readily. A plant may produce up to 500 seeds in shaded sites and up to 11,500 seeds in open sites. I find it a relatively easy weed to remove, provided it has developed a decent stem: grasp firmly and pull slowly upward. Out it comes.
Building with plant issues, Singapore.
Better get right at it. One wouldn’t want this to happen, would one?