Hibiscus tiliaceus, commonly known as the sea hibiscus or coast cottonwood, is an evergreen species of Flowering plant tree in the Malva family, Malvaceae, with a pantropical distribution along coastlines. It has also been introduced to Florida and New Zealand. It has been debated whether this species is native or introduced to Hawaii.
Names
Common names include
sea hibiscus,
beach hibiscus,
coastal (or
coast)
hibiscus,
coastal (or
coast)
cottonwood,
green cottonwood,
native hibiscus,
native rosella,
cottonwood hibiscus,
kurrajong,
sea rosemallow and
dhigga (Maldivian).
The plant was introduced by Austronesian peoples that voyaged across Southeast Asia and Oceania as a source of wood and fibre.
Description
Hibiscus tiliaceus reaches a height of , with a trunk up to in diameter.
The
of
H. tiliaceus are bright yellow with a deep red center upon opening. Over the course of the day, the flowers deepen to orange and finally red before they fall. The branches of the tree often curve over time. The leaves are heart shaped and deep red in the var.
rubra.
Distribution and habitat
Hibiscus tiliaceus has a worldwide tropical distribution. In the
Old World and
Oceania, it is a common
plant in most of tropical
Africa,
South Asia (including the
Maldives),
Southeast Asia, parts of
East Asia (as far north as central
Japan, where it reaches its northernmost extent), eastern and northern
Australia,
and much of the Pacific Islands, including
Hawaii (where its establishment status is uncertain). It has also been introduced to
New Zealand. A separate subspecies, subsp.
pernambucensis (formerly considered a separate species,
H. pernambucensis), is native to the tropical
New World, including
Mexico,
Central America, the
Caribbean, and much of
South America.
[ This variety has also been introduced to Florida.]
It is uncertain if the species is native to Hawaii, as it may have been Canoe plants by the .
Subspecies and varieties
Four subspecies and varieties are accepted.[
]
-
Hibiscus tiliaceus subsp. crestaensis – Philippines
[ Hibiscus tiliaceus subsp. crestaensis Borss.Waalk. Plants of the World Online. Retrieved 24 June 2024.]
-
Hibiscus tiliaceus subsp. pernambucensis (synonym Hibiscus pernambucensis ) – tropical Americas, from Mexico through Central America and the Caribbean to Ecuador and southern Brazil.
[ Hibiscus tiliaceus subsp. pernambucensis (Arruda) A.Cast. Plants of the World Online. Retrieved 24 June 2024.]
-
Hibiscus tiliaceus var. potteri – Hawaiian Islands
[ Hibiscus tiliaceus var. potteri (O.Deg. & Greenwell) H.St.John. Plants of the World Online. Retrieved 24 June 2024.]
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Hibiscus tiliaceus subsp. tiliaceus – west and west-central tropical Africa, east tropical Africa from Kenya to South Africa, Indian subcontinent, Indochina, southern China, Taiwan, Japan, Malesia, Papuasia, northern and eastern Australia, and the tropical Pacific islands.
[ Hibiscus tiliaceus subsp. tiliaceus. Plants of the World Online. Retrieved 24 June 2024.]
Uses
The wood of H. tiliaceus has a specific gravity of 0.6. It has been used in a variety of applications, such as seacraft construction, firewood, and . It is easy to plane and turns well, so it is regarded by many as a high quality furniture wood. Plant fibers taken from the stems have traditionally been used in rope making,
Hibiscus tiliaceus is widely used in Asian countries, especially Taiwan, as a subject for the art of bonsai. The finest specimens are taken from Kenting National Park. Lending itself to free grafting, the leaf size is reduced fairly quickly. Its leaves are also used in cooking, as trays for steamed rice cakes (Caozaiguo).
In Indonesia H. tiliaceus is also used for fermenting tempeh. The undersides of the leaves are covered in downy hairs known technically as trichomes to which the mold Rhizopus oligosporus can be found adhering in the wild. Soybeans are pressed into the leaf, and stored. Fermentation occurs resulting in tempeh.
Indigenous Australians traditionally used the inner bark of the tree to craft fishing nets and ropes, particularly for use with dugong and turtle harpoons. The wood was also employed in the making of shields. Medicinally, the inner bark and sapwood were soaked in water and heated with hot stones, producing a liquid that was applied to wash wounds. Strips of bark were additionally used as natural bandages, wrapped around injuries to cover and close them.
Chemistry
Cyanidin-3-glucoside is the major anthocyanin found in flowers of H. tiliaceus.[Lowry, J.B. (1976). "Floral anthocyanins of some Malesian Hibiscus species". Phytochemistry 15: 1395–1396.] Leaves of H. tiliaceus displayed strong free radical scavenging activity and the highest tyrosinase inhibition activity among 39 tropical plant species in Okinawa.[(Masuda et al., 1999; 2005)] With greater UV radiation in coastal areas, it is possible that leaves and flowers of natural coastal populations of H. tiliaceus have stronger antioxidant properties than planted inland populations.[(Wong et al., 2009; Wong & Chan, 2010).]
See also
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Domesticated plants and animals of Austronesia
-
Thespesia populnea
Bibliography
-
Masuda, T., Yonemori, S., Oyama, Y., Takeda, Y., Tanaka, T., Andoh, T., Shinohara, A., Nakata, M. (1999). "Evaluation of the antioxidant activity of environmental plants: activity of the leaf extracts from seashore plants". Journal of Agricultural and Food Chemistry 47: 1749–1754.
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Masuda, T., Yamashita, D., Takeda, Y., Yonemori, S. (2005). "Screening for tyrosinase inhibitors among extracts of seashore plants and identification of potent inhibitors from Garcinia subelliptica". Bioscience, Biotechnology, and Biochemistry 69: 197–201.
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Wong, S.K., Lim, Y.Y., Chan, E.W.C. (2009). "Antioxidant properties of Hibiscus: Species variation, altitudinal change, coastal influence and floral colour change". Journal of Tropical Forest Science 21(4): 307–315.
-
Wong, S.K., Chan, E.W.C. (2010). "Antioxidant properties coastal and inland populations of Hibiscus tiliaceus". ISME/GLOMIS Electronic Journal 8(1): 1–2. http://www.glomis.com/ej/pdf/EJ_8-1.pdf.
