Hibiscus

Vegetative characteristics

Hibiscus are annual or perennial, 0.1–4 m tall shrubs, subshrubs, trees, or herbs with alternate, usually stipulate, petiolate leaves with an entire or lobed margin. The leaf venation is pinnate or palmate.

Generative characteristics

The flowers are large and conspicuous. They are trumpet-shaped, with five or more petals, colour from white to pink, red, blue, orange, peach, and from 4–18 cm broad.^{[citation needed]} 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 flowering.^{[citation needed]}

Traits

Known for its hardiness, Hibiscus rosa-sinensis withstands ailments and pests, and is tough in the face of both too much water and/or drought.

Etymology

The generic name is derived from the Greek name ἱβίσκος (hibískos) which Greek botanist Pedanius Dioscorides gave to a plant now scientifically labelled as Althaea officinalis.

Distribution

Hibiscus species are numerous, and are native to a wide variety of tropical and warm temperate regions, from China to East Africa to Hawaii. In Hawaii, there is a question as to whether it was brought to the island by Polynesian settlers or is indigenous. There are 35 species which are native to the US. Scarlet rosemallow, a Hibiscus species native to Florida, thrives in wetlands, as does the less common swamp rosemallow. Rose of Sharon is not a rose, but rather a hibiscus shrub, native to both Northern Israel and Syria.

There is a great deal of hybridization via grafting of differing Hibiscus species, resulting in cultivars possessing various colors and appearance. Hot houses and indoor spaces enable the flower to thrive outside of tropical and sub-tropical areas. Often these hybrids look very different from. native species of hibiscus.

Botanical Gardens

Hibiscus is a popular plant worldwide in many botanical gardens. The planting and presenting hibiscus dates back to the 1700s at Boboli Gardens, Florence, Italy, and continues to this day.

In Fiji, a project was started to save the country's rare Hibiscus storckii from extinction, via cultivating it in the country's Savurua Botanic Garden on Viti Levu.

Many botanic gardens in the USA showcase hibiscus. The Chicago Botanic Garden contains a wide assortment of hibiscus cultivars in colors ranging from red to peach to purple. The Brooklyn Botanic Garden appreciates the heartiness and longevity of the flower, as well as its multicolored options, and along with other flowers, highlights hibiscus by its water garden. There are six endemic hibiscus species in Hawaii, which come in a variety of colors. The Limahuli Botanical Garden (Pacific Tropical Botanical Garden) is rich in a variety of species, including hibiscus. A small sampling of other American gardens which display hibiscus includes the UT Gardens (Tennessee,) the Frelinghuysen Arboretum in New Jersey, and Atlanta Botanical Garden.

Hibiscus is also well presented across Europe. Some examples of locations include Kew Gardens in London, where the rare Clay's Hibiscus is housed, preserved, and propagated. This hibiscus species is severely endangered in its native Hawaii, due to climate change, crowding out by non-native plants, and consumption by wild goats and pigs. Another site is Jardin Extraordinaire in Nantes, France, whose microclimate (several degrees warmer than the general area) allows for the growth of many tropical plants, including hibiscus. Le Gallerie Deglie Uffizi in Italy contains Hibiscus rosa-synensis. Exotic plants have been propagated in these gardens since the 1700s, and an awareness of Hibiscus existed as far back as the Medieval period, since it is mentioned by Dante in "Inferno." In Italy, Hibiscus is commonly planted for its ornamental value.

The Jerusalem Botanical Gardens, which has the most intensive compilation of plants not only in Israel, but in the entire Middle East, highlights a variety of hibiscus species, including Hibiscus schizopetalus, Hibiscus panduriformis, and Hibiscus coccineus.

Species

Several hundred species (433 in 2026) are accepted, including:

Formerly placed in the genus

Landscaping

Hibiscus species are grown for their showy flowers or used as landscape shrubs, and are used to attract butterflies, bees, and hummingbirds. In the Philippines, it is considered to be the Queen of the Garden. Hibiscus is used as an ornamental flower in tropical and sub-tropical zones worldwide.

Rope and construction

The ropes on the missionary ship Messenger of Peace were made of fibres from hibiscus trees.

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. Contrary to popular assumptions that the flowers or petals are what is being eaten, it is the calyces. Hibiscus sabdariffa, also known as "Jamaica" or roselle, is the species of hibiscus used to make herbal tea. Since it is sour, it is often mixed with honey, sugar, or cinnamon. In Tobago, it was used as fodder for animals.

Folk medicine

Hibiscus × rosa-sinensis is described as having a number of medical uses in Indian Ayurveda. In Tobago, it was used for hygienic purposes (dental.) Hibiscus has many health benefits, such as lowering blood pressure and providing antioxidants. In ancient Hawaii, chewing and swallowing the leaves was considered a natural laxative. Chewing its seeds was seen as a way of strengthening a feeble child. Extracts were used to prevent falling hair and dandruff, and other plant parts were considered valuable in fighting infections.

Precautions and contraindications

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. It is also the state flower of Hawaii.