Dysoxylum

''Dysoxylum'' is a flowering plant genus of trees and shrubs from the mahogany family, Meliaceae.

Botanical science has recorded about eighty species in this genus, growing widely across the regions of Malesia, the western Pacific ocean, Australia and south & southeastern Asia; centred on the tropics between the Pacific and Indian Oceans.

They grow naturally in New Guinea, eastern and northern Australia, New Caledonia, Fiji, SE Asia, southern China, the Indian subcontinent, the Philippines, Taiwan, and in the western Pacific Ocean their most easterly occurrences, in the Caroline Islands, New Zealand and Niue.

The etymology of its name ''Dysoxylum'' derives from the Greek word ‘''Dys''’ meaning "bad" referring to "ill-smelling" and ‘''Xylon''’ meaning "wood".

Distribution

New Guinea has records of twenty eight species growing naturally, sixteen of them endemic.
New Caledonia has recorded nine, eight of them endemic.
Fiji has recorded nine, seven of them endemic.
In northern and eastern coastal regions of Australia fifteen recorded species grow naturally, known as "rosewoods", though they are not closely related to the true rosewoods ('' Dalbergia'') which are legumes.

In Australia, '' Dysoxylum fraserianum'' is the original rose wood. The name rosewood was given for the odour of its freshly cut bark like a fragrance of roses. The species was named ‘''fraserianum''’ after Charles Fraser, the first colonial botanist of New South Wales. Fourteen more species are reported in Australia, distributed from within New South Wales, north through the humid east coast regions to the diversity of species in the wet tropics rainforests region of northeastern Queensland, on to Cape York Peninsula, northern parts of the Northern Territory and Western Australia.

New Zealand has one endemic species ''D. spectabile'', while Niue (island), further east at the global eastern limit of records of the genus, has a single species, the widespread (non-endemic) ''D. mollissimum'' subsp ''molle''.
On the remote oceanic islands within Australia's territorial waters, Lord Howe Island has one endemic species ''D. pachyphyllum''; Norfolk Island shares the restricted, but not locally endemic, ''D. bijugum'' with New Caledonia and Fiji; and Christmas Island shares a single widespread species ''D. gaudichaudianum'' with Australia, Malesia and SE Asia.

In the southern half of China eleven recorded species grow naturally, one of them endemic.

In Sri Lanka, India and nearby Bhutan and Nepal (Indian subcontinent) large trees of the genus ''Dysoxylum'' grow naturally in forests from lowlands to mid altitude mountains. About ten to twelve recognised species grow naturally in this region. Endemic Indian species: ''D. beddomei'', ''D. binectariferum'', ''D. ficiforme'' and ''D. malabaricum''. Endemic Sri Lankan species: ''D. championii''. Species occurring in India, Sri Lanka, nearby and more widely: ''D. excelsum'', ''D. gotadhora'', ''D. grande'', ''D. mollissimum'' and ''D. pallens''.
In the Indonesian Rain Forest Area of Java, the plant species reported is ''Dysoxylum caulostachyum''.

Habitats

These trees are important components of the native tropical forests of their range, such as New Guinea, the lowland New Caledonia rain forests and the tropical forests of northern Australia.
In this region more than forty different species grow naturally, from the lowlands to the mountains. In New Guinea ''D. enantiophyllum'' and an undescribed taxon have records of growing up to about altitude.

In the forests of the region of China, India, Sri Lanka and the adjacent Himalayas including Bhutan and Nepal, about fourteen recorded different species grow naturally from the lowlands to the mountains up to altitude.

In the region of southern China, Burma, Thailand, Malay Peninsula, Sumatra, Java, Lesser Sunda Islands, Borneo (Sarawak, Sabah, east Kalimantan), Philippines and Sulawesi, the ''Dysoxylum'' species most widely distributed is known as ''Dysoxylum densiflorum'' (meaning in Latin:"densely flowered"). It is found in elevation up to elevation in alluvial soil conditions (clay and sand) and along rivers and streams and also in limestone formation in undisturbed mixed dipterocarp and sub-montane forests types.

In India, it is also known by many other names such as, Indian white cedar, Bili devdari, Bombay white cedar, Velley agile, Porapa, Vella agil and Devagarige and in the evergreen forest regions of Western Ghats, North Kanara, Coorg, Anamalais, and Travancore regions.

Cultural connections

''Dysoxylum densiflorum'', locally known as '' majegau'', is the plant "mascot" or floral emblem of Bali. It is found in Bali's Botanic Garden located about 50 km to north of at Denpasar, the capital city of Bali.

A postage stamp was proposed to be issued by Indonesia on the rich flora and fauna of its provinces. It was proposed to issue 33 stamps in succession between 2008 and 2011. In 2008 the series issued represented the province of Bali with the stamp depicting floral species of ''Dysoxylum densiflorum'', known as ''Majegau'' in Indonesian language. The stamp issue described the qualities of this species as "one of woods commonly used for Balinese carving material thanks to its strength and beautiful colour and pattern". Majegau (''Dysoxylum densiflorum'') and Bali starling (''Leucopsar rothschildi'') of Bali are also part of this series.

Ecological connections

The tooth-billed pigeon (''Didunculus strigirostris'') feeds mainly on the fruits of the ''Dysoxylum'' trees growing in its native Samoa. Foliage of ''D. mollissimum'' provides food for caterpillars of the Hercules moth (''Coscinocera hercules''). Among the better-known pathogens affecting this genus is ''Pseudomonas syringae'' pv. ''dysoxylis'' which often initiates frost damage in Kohekohe.

The bio cultural studies initiated in the villages of Kerala indicated that nearly 50% of the seeds of ''Dysoxylum malabaricum'' could be raised as seedlings. ''Dysoxylum malabaricum'' known as white cedar belongs to the plant family Meliaceae, is called as ''Vella akil'' in Malayalam language, ''Vellayagil'' in Tamil language and ''Bilibudlige'' in Kannada language, all names attributing to the white colour of the species.

The tree grows to height of 40 m height, has bark which is greyish-yellow in colour with inner bark in creamy yellow colour. Its leaves alternate or sub opposite, abruptly pinnate with angular rachis. Flowers which mature during February–April are greenish yellow in colour and bisexual. Fruits that ripen during June–July are capsules. While natural regeneration process is common, artificial regeneration of seeds is also done by storing them in wet bags. The seeds are then sown in nursery beds of sand and soil at the rate of 3:1, and germination has been noted to occur within 70 days. Its chemical composition is known by the name “ashtagandha”, which means a fragrant smell, which is used for making incense sticks commonly used for worship. It is used for fumigation and also for Hindu ritual of fire sacrifice called yagna. Its wide therapeutic use, after making a decoction of the bark is for curing arthritis, anorexia, cardiac debility, to remove intestinal worms, inflammation, leprosy and rheumatism. Its oil is used for curing ear ache and eye diseases.

Uses

The Australian species were prized for their wood which is a rich red in colour and was widely used in the furniture trade. The common timber name for the Australian species is the rose mahogany. The New Zealand species, Kohekohe (''D. spectabile''), is sometimes known as New Zealand mahogany, because its wood is light, strong and polishes to a fine red colour.

Rohitukine (C16H19O5N), a chromane alkaloid, was first reported from '' Amoora rohituka'' (Roxb.) Wight & Arn. (Meliaceae) and then from ''D. binectariferum'' . Rohitukine exhibits both anti-inflammatory as well as immuno-modulatory properties besides acting as an anticancer compound. Rohitukine is an important precursor for the semi-synthetic derivative, flavopiridol (C21H20Cl NO5).

In India, apart from its economic importance for building and furniture making, it is an important ingredient in Ayurvedic Medicine as many species have curative qualities taken independtly or as an ingredient of a medicinal mixture. Some of the uses in Ayurveda reported are; Wood decoction of ''D. malabaricum'' to cure rheumatism and its oil is used to cure eye and ear diseases; a few species are used to cure inflammation, cardio-disorder, CNS disorder and also tumor. In Indian tradition and culture oil is extracted from the seeds ''Dysoxylum malabaricum'', which has wide beneficial application.

Species

The majority of this listing draws from the 1995 '' Flora Malesiana'' genus treatment by David Mabberley, with further sourcing from his 2008 ''Flora of China'' genus treatment. Then the Dec 2010 ''Australian Tropical Rainforest Plants'' identification system and the carefully cross-checked species from the older 1985 ''Flora Vitiensis'' (Fiji) add a minority number of different species.

* '' Dysoxylum acutangulum''
** subsp. ''acutangulum'' – Peninsular Thailand, Malesia: Sumatra, Malay Peninsula, Borneo, Philippines
** subsp. ''foveolatum'' – New Guinea, Solomon Is., Queensland, NT, N. Australia; Malesia: Sumatra, Java, Flores, Timor, Moluccas
* '' Dysoxylum alatum'' – New Guinea
* '' Dysoxylum aliquantulum'' – Fiji endemic
* '' Dysoxylum alliaceum'' – New Guinea, Solomon Is., coastal central QLD to the wet tropics and Cape York; throughout Malesia; Peninsular Thailand, Andaman Is., SE Asia
* '' Dysoxylum aneityense'' – Vanuatu
* '' Dysoxylum angustifolium'' – "restricted to the river systems on the east of the Malay Peninsula"
* '' Dysoxylum annae'' – NW lowland New Guinea
* '' Dysoxylum arborescens'' , Mossman mahogany – New Guinea, Pacific Is. incl. Solomon Is., Vanuatu; Queensland wet tropics, Cape York; throughout Malesia incl. Philippines, Borneo, Sumatra; Andaman Is., Nicobar Is., Taiwan
* '' Dysoxylum beddomei'' – India
* '' Dysoxylum bijugum'' ; Synonyms: ''D. patersoni, D. patersonianum'' – Fiji, New Caledonia, Norfolk Is.
* ''Dysoxylum binectariferum'' – India to Vietnam
* '' Dysoxylum boridianum'' – New Guinea. Only Boridi village, Port Moresby district, central PNG
* '' Dysoxylum brachybotrys'' – Malesia: Borneo, Philippines
* '' Dysoxylum brassii'' – New Guinea
* '' Dysoxylum brevipaniculum'' – central eastern New Guinea
* '' Dysoxylum canalense'' – New Caledonia endemic
* '' Dysoxylum carolinae'' – Vietnam; Malesia: Sumatra, Malay Peninsula, Borneo
* '' Dysoxylum cauliflorum'' – Vietnam, Cambodia, Thailand; Malesia: Sumatra, Bangka, Malay Peninsula, Borneo, Philippines, Burma
* '' Dysoxylum championii'' – Sri Lanka
* '' Dysoxylum crassum'' – Borneo
* '' Dysoxylum cumingianum'' – Taiwan, Philippines, Sulawesi, Bali, Moluccas, Malaysia
* '' Dysoxylum cyrtobotryum'' – SE Asia to Malesia: Nicobar Is., Andaman Is., Sumatra, Malay Peninsula, Borneo, Java, Bali, Flores, Philippines
* '' Dysoxylum densiflorum'' – S. Burma, S. China, Thailand; Malesia: Sumatra, Malay Peninsula, Borneo, Java, Sulawesi, Bali, Lombok, Flores; Bali floral emblem, known as Majegau
* '' Dysoxylum dumosum'' – Malesia: Malay Peninsula, Sumatra
* '' Dysoxylum enantiophyllum'' – New Guinea
* '' Dysoxylum excelsum'' – New Guinea, Solomon Is., S. China, Bhutan, Laos, NE. India, Sri Lanka, Nepal; Andaman Is.; throughout Malesia incl. Philippines; Indochina incl. Thailand, Vietnam

* '' Dysoxylum flavescens'' – Malesia: Sumatra, Malay Peninsula, Borneo
* '' Dysoxylum fraserianum'' – eastern subtropical Australian rainforests, New South Wales, Queensland
* ''Dysoxylum gaudichaudianum'' , ivory mahogany; Synonyms: ''D. amooroides, D. blancoi, D. decandrum, D. maota, D. rufum'' var. ''glabrescens, D. salutare'' – New Guinea, eastern Queensland, Christmas Is., Bismarck Archipelago, SW Pacific Is.: Solomon Is. Vanuatu, Samoa; Malesia: Java, Sumbawa, Flores, Timor, Sulawesi, Philippines, Moluccas
* '' Dysoxylum gillespieanum'' – Fiji endemic
* '' Dysoxylum gotadhora'' – S. China, Hainan, Bhutan, India, Laos, Nepal, Thailand, Vietnam - Syn. ''Dysoxylum ficiforme'' – India
* '' Dysoxylum grande'' ; Synonym: ''D. verruculosum'' – NE India (Assam), S. China, Vietnam, Thailand, Hainan, Bhutan; Malesia: Sumatra, Malay Peninsula, Borneo, Philippines
* '' Dysoxylum hapalanthum'' – north-east New Guinea
* '' Dysoxylum hoaense'' – Vietnam
* '' Dysoxylum hongkongense'' – S China, Hainan, Taiwan
* '' Dysoxylum hornei'' – Fiji endemic
* '' Dysoxylum huntii'' – Samoa endemic, known as Maota mea.
* '' Dysoxylum inopinatum'' – northern and central New Guinea
* '' Dysoxylum juglans'' – Laos, Vietnam
* ''Dysoxylum kaniense'' – New Guinea, Solomon Is.
* '' Dysoxylum klanderi'' – Queensland wet tropics endemic
* '' Dysoxylum kouiriense'' – New Caledonia endemic
* '' Dysoxylum latifolium'' – New Guinea, Solomon Is., Queensland wet tropics, Cape York, NT, Western Australia
* '' Dysoxylum lenticellare'' – Fiji endemic
* '' Dysoxylum lenticellatum'' – S. China, Burma, Thailand
* '' Dysoxylum loureirii'' – Vietnam
* '' Dysoxylum macranthum'' – New Caledonia endemic
* '' Dysoxylum macrocarpum'' – Thailand; Malesia: Sumatra, Malay Peninsula, Borneo, Sulawesi, Java, Philippines
* '' Dysoxylum macrostachyum'' – New Caledonia endemic
* '' Dysoxylum magnificum'' – SE Sumatra, Borneo
* '' Dysoxylum malabaricum'' – ml, Akil, India

* '' Dysoxylum minutiflorum'' – New Caledonia endemic
* '' Dysoxylum mollissimum'' ; Synonyms: ''D. forsteri'', ''D. muelleri'' – E. India, S. China, throughout Malesia, to Australia and W. Pacific
** subsp. ''molle'' ; Synonyms: ''D. forsteri'', ''D. molle'', ''D. quercifolium'', ''D. richii'' , ''D. samoense'' – New Guinea, Bismarck Archipelago, Solomon Is., Vanuatu, N to Carolines; NE NSW, eastern Queensland; Pacific Is.: Fiji, Samoa, Tonga, E to Niue; Malesia: Flores, Timor, Wetar, Moluccas, W to Sulawesi
** subsp. ''mollissimum'' – India (Assam, Sikkim), Bhutan, Burma, S. China (Yunnan, Hainan); Malesia: Sumatra, Malay Peninsula, Borneo, Java, Philippines, Bali
* '' Dysoxylum myriandrum'' – Fiji endemic
* '' Dysoxylum nutans'' – Malesia: Sumatra, Java, Sulawesi, Bali, Sumbawa, Flores, Moluccas
* '' Dysoxylum oppositifolium'' , pink mahogany – New Guinea, Solomon Is., Queensland wet tropics, Cape York, NT; Malesia incl.: Borneo, Philippines, Sumba, Flores
* '' Dysoxylum pachyphyllum'' ; Synonym: ''D. fraserianum'' auct. non – Lord Howe Island endemic
* '' Dysoxylum pachypodum'' – New Caledonia endemic
* '' Dysoxylum pachyrhache'' – Borneo
* '' Dysoxylum pallens'' – S. China, Hainan, Bhutan, Cambodia, India, Burma, Thailand
* '' Dysoxylum papillosum'' – Peninsular Thailand; Malesia: Malay Peninsula, Borneo
* '' Dysoxylum papuanum'' , spicy mahogany – New Guinea, Australian wet tropics through to coastal central Queensland, Solomon Is.

* ''Dysoxylum parasiticum'' , yellow mahogany – Queensland wet tropics, Cape York, New Guinea, Bismarck Archipelago, Solomon Is.; Malesia: Sumatra, E Borneo, Sulawesi, Lombok, Sumba, Sumbawa, Flores, Tanimbar, Timor, Moluccas, Philippines, Taiwan
* '' Dysoxylum pauciflorum'' – Philippines
* '' Dysoxylum pettigrewianum'' – New Guinea, Bismarck Archipelago: New Britain, Solomon Is., Moluccas, Queensland wet tropics
* '' Dysoxylum phaeotrichum'' – few sites in central New Guinea
* '' Dysoxylum pumilum'' – Queensland wet tropics endemic
* '' Dysoxylum randianum'' – New Guinea
* '' Dysoxylum rigidum'' – Malesia: SE Sumatra, Malay Peninsula, Borneo
* '' Dysoxylum roseum'' – New Caledonia endemic

* '' Dysoxylum rubrocostatum'' - Vietnam
* '' Dysoxylum rufescens''
** subsp. ''dzumacense'' – New Caledonia endemic
** subsp. ''rufescens'' – New Caledonia endemic
* ''Dysoxylum rufum'' , hairy rosewood – NE NSW, eastern Queensland; Australian endemic
* '' Dysoxylum rugulosum'' – Malesia: Sumatra, Malay Peninsula, Borneo
* '' Dysoxylum seemannii'' – Fiji endemic
* '' Dysoxylum sessile'' – Malesia: Moluccas
* '' Dysoxylum setosum'' – Queensland wet tropics, Cape York, New Guinea, Timor
* '' Dysoxylum sparsiflorum'' – New Guinea
* ''Dysoxylum spectabile'' , kohekohe, New Zealand mahogany
* '' Dysoxylum stellatopuberulum'' – New Guinea
* '' Dysoxylum tenuiflorum'' – Fiji endemic
* '' Dysoxylum tongense'' – Tonga endemic
* ''Dysoxylum variabile'' – New Guinea, Bismarck Archipelago, Solomon Is.
* '' Dysoxylum yunzaingense'' – eastern New Guinea

References

Cited works

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{{Taxonbar, from=Q949885

Meliaceae genera