Mirabilis

Mirabilis 

a genus of generally perennial herbaceous plants of the family Nyctagynaceae. The roots are often thickened. The leaves are opposite and entire. The regular flowers are bisexual and grow in many-flowered inflorescences. The corolla is purple, white, or yellow and consists of five (sometimes three to seven) long, fused bracts. After the plant blossoms, the bracts greatly increase in size and surround the fruit. Each flower (less commonly, only some of the flowers) has a calyxlike involucre.

There are 60 species, distributed from central North America to Chile. Of the many decorative species, the best known is the four-o’clock (Mirabilis jalapa), whose garden forms have variously colored, variegated flowers. Four-o’clocks open toward evening and remain fully open until morning; in cloudy weather they are open during the day as well.