The four o'clock flower is an ornamental flower that is also known as Mirabilis jalapa and Marvels of Peru. It is one of the most well-known Mirabilis species, and comes in various different colors. The flower received its unusual name due to its habit of always opening up during the late afternoon, around four o'clock.
The four o'clock flower originated in South America's tropical regions. However, the flower thrives in warm, temperate and tropical areas. The four o'clock thrives in full sun, and grows to a height of approximately 3 feet. It self-seeds, and quickly spreads if left unmonitored. It is beneficial to completely soak the seeds before commencing planting. The flower is a perennial in the USDA's plant hardiness zones 9 and 10. However, four o'clock flower can grow in all zones.
The four o'clock flowers are leafy and similar to shrubs. The perennials are multi-branched and bear flowers for the entire summer. The flowers are spreading and erect, and grow to between 2 and 3 feet in height, and to about the same width. They have pointed and opposite leaves, and several branches. The flowers are fragrant and are borne either in clusters or by themselves. They can be bicolored, white, yellow, pink or magenta and are shaped like trumpets of about 2 inches in length, and 1 inch in width.
The four o'clock flower is a popular ornamental plant in gardens but has various other uses. An edible red dye is extracted from the flowers and used as food coloring in jellies, jams and cakes. In South America, the root of the flower is used as an hallucinogen and for medicinal purposes. Sections of the plant can be used as a purgative or diuretic, or for treating wounds. The leaves also can be used to decrease inflammation. The leaves of the flower can be consumed if cooked.
The four o'clock flower earned its name due to the fact that it opens late in the afternoon. The flower then stays open all night, and closes in the wee hours of the morning. On days that are cloudy, the four o'clock stays open. This is unusual, as most flowers open up the morning. The reason is that they must lure insect pollinators, which are mostly active in the daytime.
When powdered, the seeds of various types of four o'clock flowers are used for dye and cosmetics. However, the seeds are highly poisonous and should be kept away from children and pets. The seeds are black and small, and have wrinkled surfaces. They appear similar to pepper grains.