Hibiscus 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 those species are commonly known simply as "hibiscus", or less widely known as rose mallow. Other names include hardy hibiscus, rose of sharon, and tropical hibiscus.
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 name ἰβίσκος (ibískos) which Pedanius Dioscorides gave to Althaea officinalis (c. 40–90 AD).
Several species are widely cultivated as ornamental plants, notably Hibiscus syriacus and Hibiscus rosa-sinensis.
A tea made from the flowers of Hibiscus sabdariffa is known by many names around the world and is served both hot and cold. The beverage is known for its red colour, tart flavour, and vitamin C content.


== Description ==
The leaves are alternate, ovate to lanceolate, often with a toothed or lobed margin (dentate). The flowers are large, conspicuous, trumpet-shaped, with five or more petals, colour from white to pink, red, blue, orange, peach, yellow or purple, and from 4–18 cm broad.

Flower colour 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.


== Species ==

In temperate zones, probably the most commonly grown ornamental species is Hibiscus syriacus, the common garden hibiscus, also known in some areas as the "rose of Althea" or "rose of Sharon" (but not to be confused with the unrelated Hypericum calycinum, also called "rose of Sharon"). In tropical and subtropical areas, the Chinese hibiscus (H. rosa-sinensis), with its many showy hybrids, is the most popular hibiscus.
Several hundred species are known, including:


=== Formerly placed in the genus ===


== Uses ==


=== Landscaping ===
Many species are grown for their showy flowers or used as landscape shrubs, and are used to attract butterflies, bees, and hummingbirds.
Hibiscus is a very hardy, versatile plant and in tropical conditions it can enhance the beauty of any garden. Being versatile it adapts itself easily to balcony gardens in crammed urban spaces and can be easily grown in pots as a creeper or even in hanging pots. It is a perennial and flowers throughout the year. As it comes in a variety of colors, it's a plant which can add vibrancy to any garden.
The only infestation that gardeners need to be vigilant about is mealybugs. Mealybug infestations are easy to spot as they are clearly visible as a distinct white cottony infestation on buds, leaves or even stems. To protect the plant you need to trim away the infected part, spray with water, and apply an appropriate pesticide.


=== Paper ===
One species of Hibiscus, known as kenaf (Hibiscus cannabinus), is extensively used in paper-making.


=== Rope and construction ===
The inner bark of the sea hibiscus (Hibiscus tiliaceus), also called 'hau', is used in Polynesia for making rope, and the wood for making canoe floats. The ropes on the missionary ship Messenger of Peace were made of fibres from hibiscus trees.


=== Beverage ===

The tea made of the calyces of Hibiscus sabdariffa is known by many names in many countries around the world and is served both hot and cold. The beverage is well known for its red colour, tartness and unique flavour. Additionally, it is highly nutritious because of its vitamin C content.
It is known as bissap in West Africa, "Gul e Khatmi" in Urdu & Persian, agua de jamaica in Mexico and Central America (the flower being flor de jamaica) and Orhul in India. Some refer to it as roselle, a common name for the hibiscus flower. In Jamaica, Trinidad and many other islands in the Caribbean, the drink is known as sorrel (Hibiscus sabdariffa; not to be confused with Rumex acetosa, a species sharing the common name sorrel). In Ghana, the drink is known as soobolo in one of the local languages.
In Cambodia, a cold beverage can be prepared by first steeping the petals in hot water until the colors are leached from the petals, then adding lime juice (which turns the beverage from dark brown/red to a bright red), sweeteners (sugar/honey) and finally cold water/ice cubes.
In Egypt and Sudan, hibiscus tea is known as karkadé (كركديه), and is served as both a hot and a cold drink.
Hibiscus (also known in Sri Lanka as shoe flower, සපත්තු මල, වද මල in Sinhalese) is an ingredient with a rich heritage of refreshing Lankans. Fresh juices, ice teas and syrups made of the Hibiscus flower are famous refreshments among Sri Lankans.


=== Food ===
Dried hibiscus is edible, and it is often a delicacy in Mexico. It can also be candied and used as a garnish, usually for desserts.
The roselle (Hibiscus sabdariffa) is used as a vegetable.
The species Hibiscus suratensis Linn synonymous with Hibiscus aculeatus G. Don is noted in Visayas in the Philippines as being a souring ingredient for almost all local vegetables and menus. Known as labog in the Visayan area (or labuag/sapinit in Tagalog), the species is an ingredient in cooking native chicken soup.
Hibiscus species are used as food plants by the larvae of some lepidopteran species, including Chionodes hibiscella, Hypercompe hambletoni, the nutmeg moth, and the turnip moth.


=== Folk medicine ===
Hibiscus rosa-sinensis is described as having a number of medical uses in Indian Ayurveda.


=== Claimed effects on blood pressure ===
It has been claimed that sour teas derived from Hibiscus sabdariffa may lower blood pressure.


=== Precautions and contraindications ===


==== Pregnancy and lactation ====
While the mechanism is not well understood, previous animal studies have demonstrated both an inhibitory effect of H. sabdariffa on muscle tone and the anti-fertility effects of Hibiscus rosa-sinensis, respectively. The extract of H. sabdariffa has been shown to stimulate contraction of the rat bladder and uterus; the H. rosa-sinensis extract has exhibited contraceptive effects in the form of estrogen activity in rats. These findings have not been observed in humans. The Hibiscus rosa-sinensis is also thought to have emmenagogue effects which can stimulate menstruation and, in some women, cause an abortion. Due to the documented adverse effects in animal studies and the reported pharmacological properties, the H. sabdariffa and H. rosa-sinensis are not recommended for use during pregnancy.


==== Drug interactions ====
It is postulated that H. sabdariffa interacts with diclofenac, chloroquine and acetaminophen by altering the pharmacokinetics. In healthy human volunteers, the H. sabdariffa extract was found to reduce the excretion of diclofenac upon co-administration. Additionally, co-administration of Karkade (H. sabdariffa), a common Sudanese beverage, was found to reduce chloroquine bioavailability. However, no statistically significant changes were observed in the pharmacokinetics of acetaminophen when administered with the Zobo (H. sabdariffa) drink. Further studies are needed to demonstrate clinical significance.


== Symbolism and culture ==
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 Kali and the god Ganesha in Hindu worship.
In the Philippines, the gumamela (the 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. It is also called "Tarukanga" in Waray, particularly in Eastern Samar province.
The hibiscus flower is traditionally worn by Pacific island women, and is a known shared custom that if the flower is worn behind the left ear, the woman is married or has a boyfriend. If the flower is worn on the right, she is single or openly available for a relationship. The pink hibiscus flower has its origins in Asia and the Pacific Islands, where it has served as a symbol of beauty, femininity, and young love. It is commonly associated with the Hawaiian culture and the Aloha spirit, which celebrates love, happiness, and peace. 
A stylized image of the hibiscus flower was used as a logo of Air Polynésie.
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.
A coastal area in Auckland, New Zealand is known as the Hibiscus Coast, named after the non-native flower due to its associations with beach and holiday atmospheres.


=== As a national and state symbol ===
The hibiscus is a national symbol of Haiti, and the national flower of nations including the Solomon Islands and Niue. Hibiscus syriacus is the national flower of South Korea, and Hibiscus rosa-sinensis is the national flower of Malaysia. Hibiscus brackenridgei is the state flower of Hawaii.


== References ==


== External links ==

Plant of the Month: Hibiscus at JSTOR Daily
American Hibiscus Society (AHS)
Australian Hibiscus Society
International Hibiscus Society
Vicki J. Coldwell Plant and care Hibiscus
Foundation for Revitalisation of Local Health Traditions

Dressler, S.; Schmidt, M. & Zizka, G. (2014). "Hibiscus". African plants – a Photo Guide. Frankfurt/Main: Forschungsinstitut Senckenberg.