Hibiscus (/hᵻˈbɪskəs/ or /haɪˈbɪskəs/) is a genus of flowering plants in the mallow family, Malvaceae. The genus is quite large, comprising several hundred species that are native to warm-temperate, subtropical and tropical regions throughout the world. Member species are renowned for their large, showy flowers and are commonly known simply as hibiscus, or less widely known as rose mallow. The genus includes both annual and perennial herbaceous plants, as well as woody shrubs and small trees. The generic name is derived from the Greek word ἱβίσκος (hibískos), which was the name Pedanius Dioscorides (c. 40–90) gave to Althaea officinalis.

The leaves are alternate, ovate to lanceolate, often with a toothed or lobed margin. The flowers are large, conspicuous, trumpet-shaped, with five or more petals, color from white to pink, red, orange, peach, yellow or purple, and from 4–18 cm broad. Flower color in certain species, such as H. mutabilis and H. tiliaceus, changes with age. The fruit is a dry five-lobed capsule, containing several seeds in each lobe, which are released when the capsule dehisces (splits open) at maturity. It is of red and white colours. It is an example of complete flowers.

The hibiscus is the national flower of Haiti and is used in their national tourism slogan of Haïti: Experience It! The hibiscus species also represents several other nations. The Hibiscus syriacus is the national flower of South Korea, and Hibiscus rosa-sinensis is the national flower of Malaysia. The red hibiscus is the flower of the Hindu goddess Kali, and appears frequently in depictions of her in the art of Bengal, India, often with the goddess and the flower merging in form. The hibiscus is used as an offering to goddess Kali and Lord Ganesha in Hindu worship.[citation needed]

In the Philippines, the gumamela (local name for hibiscus) is used by children as part of a bubble-making pastime. The flowers and leaves are crushed until the sticky juices come out. Hollow papaya stalks are then dipped into this and used as straws for blowing bubbles. Together with soap, hibiscus juices produce more bubbles.

The hibiscus flower is traditionally worn by Tahitian and Hawaiian girls. If the flower is worn behind the left ear, the woman is married or in a relationship. If the flower is worn on the right, she is single or openly available for a relationship.[citation needed] The hibiscus is Hawaii’s state flower.

Nigerian author Chimamanda Ngozi Adichie named her first novel Purple Hibiscus after the delicate flower.

The bark of the hibiscus contains strong bast fibres that can be obtained by letting the stripped bark set in the sea to let the organic material rot away.