Hibiscus trionum, the Flower-of-an-Hour, is an annual plant that is native to the east of the Mediterranean in the Levant, It has spread throughout southern Europe both as a weed and cultivated as a garden plant. It has been introduced to the United States as an ornamental where it has become naturalized as a weed of cropland and vacant land.
The plant grows to a height of 20-50 cm, sometimes as much as 80 cm, and has white or yellow flowers with a purple centre.