Dysoxylum
Dysoxylum gotadhora fruits and leaves
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Sapindales
Family:	Meliaceae
Subfamily:	Melioideae
Genus:	Dysoxylum Blume ex Raspail (1827)
Type species
Dysoxylum macrocarpum (Spreng.) Blume ex G.Don[2]
Species[1]
34, see text
Synonyms[1]
List Alliaria Rumph ex Kuntze (1891) (non Heist. ex Fabr.: nom. illeg., nom. superfl., preoccupied) Disoxylon Rchb. (1837), orth. var. Disoxylum A.Juss. (1830 publ. 1831), orth. var. Disyphonia Griff. (1854), nom. provis. Dysoxylon Bartl. (1830), orth. var.) Harpagonia Noronha (1790), nom. nud. Lachanodendron Reinw. (1823), nom. nud. Plutea Noronha (1790), nom. nud.

Dysoxylum is a genus of rainforest trees and shrubs in the flowering plant family Meliaceae. About 34 species are recognised in the genus, distributed from India and southern China, through southeast Asia to New Guinea, Solomon Islands, and Australia.^[1] The name Dysoxylum derives from the Greek word ‘Dys’ meaning "bad" referring to "ill-smelling" and ‘Xylon’ meaning "wood".^[3][4]

The genus ranges from the Indian subcontinent to Indochina, southern China, Malesia, New Guinea and the Solomon and Santa Cruz Islands, and northern and eastern Australia.^[1]

Eight species are native to the Indian subcontinent.^[5] 15 species are native to Indochina,^[6] and 6 are native to southern China.^[7] 13 species are native to Malesia,^[8] and seven species to Papuasia (New Guinea, the Bismarck Archipelago, and Solomon Islands) and the Santa Cruz Islands.^[9]

Four species – Dysoxylum acutangulum, D. latifolium, D. oppositifolium, and D. pumilum – are native to Australia.^[10] They grow in northwestern New South Wales, the humid east coast regions of Queensland including the wet tropics rainforests region of northeastern Queensland and Cape York Peninsula, and the northern parts of the Northern Territory and Western Australia.^[11][4]

In the Indian subcontinent, including India, Bhutan, Nepal, and Sri Lanka, large trees of the genus Dysoxylum grow naturally in forests from lowlands to mid-elevation mountains. Eight species are native to the region. D. beddomei, D. malabaricum, D. purpureum, and D. swaminathanianum are endemic to southwestern India. D. cyrtobotryum, D. gotadhora, D. grande, and D. pallens are native to the Indian subcontinent and southeast Asia.^[5][12][13]

These trees are important components of the native tropical forests of their range, such as New Guinea and the tropical forests of northern Australia.^[12][11] In this region, more than forty different species grow naturally, from the lowlands to the mountains.^[12] In New Guinea, D. enantiophyllum and an undescribed taxon have records of growing up to about 3,000 m (9,800 ft) elevation.^[12]

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 1,700 m (5,600 ft) elevation.^[14]

In India, Dysoxylum malabaricum is known by many other names such as Indian white cedar, Bilidevdari (ಬಿಳಿದೇವದಾರು), Bombay white cedar, Velley agile, Porapa, Vella agil, and Devagarige (ದೇವರಿಗೆ). It grows in the evergreen forest regions of Western Ghats, North Kanara, Coorg, Anaimalai Hills, and Travancore regions.^[15]

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 (aka D. gotadhora) 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 independently 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.^[13] In Indian tradition and culture oil is extracted from the seeds Dysoxylum malabaricum, which has wide beneficial application.^[16]

The genus Dysoxylum was erected in 1825 by the German-Dutch botanist Carl Ludwig Blume to accommodate some newly discovered plant species from Java. Over the years many changes were made to the genus, and by the late 20th century it was clear that Dysoxylum had become polyphyletic. A 2021 revision of the genus (which by then had come to include 94 species) confirmed the polyphyly and the authors reinstated several genera which had previously been considered synonyms of Dysoxylum – Didymocheton, Epicharis, Goniocheton, Prasoxylon, and Pseudocarapa – in order to accommodate their findings.^[2]

The authors (Holzmeyer et al.) proposed a circumscription (i.e. a concept of included species) of the genus that included 28 species, plus one subspecies. Following the publication of the 2021 paper, Plants of the World Online (POWO) revised their own circumscription of the genus to include 34 species. Of the 28 species proposed by Holzmeyer et al., only 23 are accepted by POWO, and there are 11 species included by POWO that were not proposed by Holzmeyer et al.^[1][2]

34 species are currently accepted by Plants of the World Online.^[1]

Wikimedia Commons has media related to Dysoxylum.

• F.A. Zich; B.Hyland; T. Whiffen; R.A. Kerrigan. "Australian Tropical Rainforest Plants Home". Australian Tropical Rainforest Plants (RFK8). Centre for Plant Biodiversity Research, Australian Government. Retrieved 26 May 2021.
• Mabberley, David J.; Pannel, C. M.; Sing, A. M. (1995). "Dysoxylu". Flora Malesiana (Digitised, online). Series I, Spermatophyta : Flowering Plants: Vol. 12 pt. 1: Meliaceae. Leiden, The Netherland: Rijksherbarium / Hortus Botanicus, Leiden University. pp. 61–133. ISBN 90-71236-26-9. Retrieved 20 January 2021.

• Peng, Hua; Mabberley, David J. (2008). Wu, Z. Y.; Raven, P. H. (eds.). "Dysoxylum Blume". Flora of China. Online version. eFloras.org. Beijing and St. Louis, MO: Science Press and Missouri Botanical Garden Press. Retrieved 26 June 2013.