Melaleuca cajuputi

Melaleuca cajuputi, commonly known as cajuput or white samet is a plant in the myrtle family, Myrtaceae and is widespread in Australia, Southeast Asia, New Guinea and the Torres Strait islands. It is a medium to tall tree with papery bark, silvery new growth and white or greenish flower spikes. It has important uses as a source of cajuput oil.

Cajuput
M. cajuputi flowers and leaves
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Myrtales
Family:	Myrtaceae
Genus:	Melaleuca
Species:	M. cajuputi
Binomial name
Melaleuca cajuputi Powell

Description

Melaleuca cajuputi is usually a medium to large tree, often growing to 35 metres (100 ft) and sometimes to 46 metres (200 ft) with grey, brownish or whitish papery bark. The new growth is silky-hairy, becoming glabrous as it matures. The leaves are arranged alternately 40–140 millimetres (2–6 in) long and 7.5–60 millimetres (0.3–2 in) wide, tapering at both ends. The flowers are white, cream or greenish-yellow mostly in dense spikes at the ends of the branches which continue to grow after flowering but also often in the axils of the upper leaves. The spikes contain 8 to 20 groups of flowers, each group with three flowers. The stamens are grouped in five bundles around the flower, each bundle containing 6 to 18 stamens. Timing of flowering varies with subspecies. The fruits are woody, cup-shaped capsules clustered loosely along the branches, each fruit 2–2.8 millimetres (0.08–0.1 in) long.[1][2]

M. cajuputi habit

Taxonomy and naming

Melaleuca cajuputi was first formally described in 1809 by Thomas Powell in Pharmacopoeia of the Royal College of Physicians of London with a reference to an earlier (1747) description by Rumphius in Herbarium Amboinense.[3] The specific epithet (cajuputi) is "probably a corruption of the Indonesian name for the plant, kayu putih".[2]

Subspecies

There are 3 subspecies:

• Melaleuca cajuputi Powell subsp. cajuputi:[4] The nominate subspecies has leaves 7–26 millimetres (0.3–1 in) wide, 7 to 10 stamens per bundle and flowers from March to November.[1][2]
• Melaleuca cajuputi subsp. cumingiana (Turcz.) Barlow:[5] This subspecies flowers from February to December and has leaves 40–200 millimetres (2–8 in) long and 10–20 millimetres (0.4–0.8 in)wide and there are 7 to 9 stamens per bundle.[6]
• Melaleuca cajuputi subsp. platyphylla Barlow:[7] This subspecies has leaves (15–60 millimetres (0.6–2 in) wide), more stamens (8–13 per bundle) and flowers from January to May and August to September.[1][2] The name platyphylla is from the Greek platys meaning "flat", "broad", "wide" or "level"[8]^:167 and phyllon meaning “leaf”.[8]^:605

Distribution and habitat

Melaleuca cajuputi Powell subsp. cajuputi occurs in the Dampier Peninsula, Calder River, Fitzroy Crossing district in the Central Kimberley biogeographic zone in Western Australia,[9] the northern part of the Northern Territory, and East Timor. It grows in woodland, vine forest, gallery forest and savannah forest, on clayey and peaty loam.[2]

Melaleuca cajuputi subsp. cumingiana (Turcz.) Barlow occurs in Myanmar, Thailand, Vietnam, Malaysia and Indonesia (Sumatra, West Java and south-west Kalimantan). The name cumingiana is "in honour of Hugh Cuming". It grows in coastal swamp forest.[2] In Thailand, the species is known as White Samet.[10]

Melaleuca cajuputi subsp. platyphylla Barlow occurs in New Guinea, the Torres Strait islands and north-western Queensland as far south as Cairns. It grows in similar habitats to subsp. cajuputi.[2]

Uses

Timber

In Southeast Asia, Melaleuca cajuputi is used as a fuel and for making charcoal. It is used on a small scale for supporting columns, frames and floorboards in house construction and for fences. The bark has been used as roofing material and a sealant in boat construction including as a caulking material for boats in Indonesia.[2][10]

Essential oils

Indigenous Australian people used the leaves of this species to treat aches and pains and inhaled vapours from the crushed leaves to treat respiratory infections.[11] In Thailand the leaves are used to make a herbal tea as a treatment for a range of medical problems. In many parts of Asia, the oil which gives the tree its name - cajuput oil is used as a liniment and inhalant.[2][10]

Commercial cajuput oil is mostly obtained from Melaleuca cajuputi subsp. cajuputi. This oil is a pale yellow liquid and contains up to 60% 1,8-cineole, the main antimicrobial component of the oil . Cajuput oil has been classified as non-toxic and non-sensitizing, although skin irritation may occur at high concentrations. It has been reported to be useful as an insect repellant, as a sedative and relaxant and is useful in treating roundworms and urino-genital infections. It is used to flavour foods and to add to the fragrance of soaps and cosmetics.[11]

References

1. Holliday, Ivan (2004). Melaleucas : a field and garden guide (2nd ed.). Frenchs Forest, N.S.W.: Reed New Holland Publishers. pp. 38–39. ISBN 1876334983.
2. Brophy, Joseph J.; Craven, Lyndley A.; Doran, John C. (2013). Melaleucas : their botany, essential oils and uses. Canberra: Australian Centre for International Agricultural Research. pp. 104–105. ISBN 9781922137517.
3. "Melaleuca cajuputi". APNI.
4. "Melaleuca cajuputi subsp. cajuputi". APNI. Retrieved 19 March 2015.
5. "Melaleuca cajuputi subsp. cumingiana". APNI. Retrieved 19 March 2015.
6. "Flora of China" (PDF). eFloras.org. eFloras.org. Retrieved 19 March 2015.
7. "Melaleuca cajuputi subsp. platyphylla". APNI. Retrieved 19 March 2015.
8. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.
9. "Melaleuca cajuputi". FloraBase. Western Australian Government Department of Parks and Wildlife.
10. Nuyim, Tanit. "Potentiality of Melaleuca cajuputi Powell cultivation to develop for economic plantation purpose". Forest management and forest products research office. Retrieved 19 March 2015.
11. Doran, John C. (1999). Southwell, Ian; Lowe, Robert (eds.). Tea tree : the genus melaleuca. Amsterdam: Harwood Academic. pp. 221–224. ISBN 9057024179.

External source

• Herbarium Amboinense. 2. 1747.