Didymocheton muelleri

Miva mahogany
Miva Mahogany at the Royal Botanic Gardens Sydney
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Meliaceae
Genus: Didymocheton
Species:
D. muelleri
Binomial name
Didymocheton muelleri
(Benth.) Mabb. (2021)
Synonyms[2]
  • Alliaria muelleri (Benth.) Kuntze (1891)
  • Dysoxylum muelleri Benth. (1863)
  • Hartighsea trichosiphane F.Muell. ex C.DC. (1878)

Didymocheton muelleri, the red bean or Miva mahogany, is a rainforest tree in the family Meliaceae.[3] It occurs in tropical, sub-tropical and littoral rainforests in eastern Australia, from the Bellinger River in New South Wales in the south, to the wet tropics of north-eastern Queensland.[3][4] A signposted red bean tree may be seen near the car park of Victoria Park Nature Reserve in north-eastern New South Wales.

Description

It is a large and impressive tree, up to 35 metres (115 ft) tall with a trunk diameter of 120 cm (47 in). It is usually buttressed or flanged at the base. The trunk is scaly and rough, grey or brown in colour. Freshly cut bark has an onion type scent.[5]

Leaves

Leaflets are usually opposite on the stem, without serrations, and distinctly asymmetrical at the leaf base. Leaflets are 6 to 15 cm (2.4 to 5.9 in) long and 2 to 5 cm (0.79 to 1.97 in) wide,[3] and are mid green above, paler below, and sometimes softly hairy under the leaf. True leaves are 30 to 60 cm (12 to 24 in) long, pinnate. Leaf stem swollen where joining the larger branch. Leaf venation is evident above and below, but raised and more noticeable below. Net veins easily seen. Veins creamy green, contrasting with the darker leaf colour.

Flowers and fruit

White flowers form on panicles from January to July. The fruit is a fawnish brown capsule, around 2 cm (0.79 in) in diameter. There is one reddish brown seed in each of the one to five cells. The fruit, which is bird attracting, ripens between November and March.[6] Fresh seed is advised for regeneration.

Taxonomy

The species was first described as Dysoxylum muelleri by George Bentham in 1863. In 1994 David Mabberley reclassified it as Dysoxylum mollissimum subsp. molle, including both the Australian populations and those in Sulawesi, Maluku, New Guinea, and the Bismarck Archipelago. A 2021 study by Holzmeyer, Hauenschild, Mabberley, et al. concluded that Dysoxylum was polyphyletic, and that the Australian population constituted a distinct species from the northern population. The species was placed in the revived genus Didymocheton, with the Australian population under the new combination Didymocheton muelleri, and the northern Sulawesi-to-Bismarck Archipelago population renamed Didymocheton mollis.[7] The Australian population is still widely known as Dysoxylum mollisimum subsp. molle.

Conservation

This species has been assessed by the Queensland Department of Environment and Science as least concern.[1]

Timber

The tree produces a well regarded mahogany timber, suited to cabinet work, carving and boat building. It is reddish brown and easily worked.[5] Sapwood is creamy pink[8] and not resistant to termites.[6] There is concern of inhaling wood dust from this tree.[9]

Red bean, Royal Botanic Gardens, Sydney

References

  1. ^ a b "Species profile—Didymocheton muelleri". Queensland Department of Environment and Science. Queensland Government. 2022. Retrieved 18 February 2024.
  2. ^ "Didymocheton muelleri (Benth.) Mabb". Plants of the World Online. Royal Botanic Gardens, Kew. 2024. Retrieved 18 February 2024.
  3. ^ a b c Taylor, M. J.; Harden, G. J. (2002). "Dysoxylum mollissimum subsp. molle – New South Wales Flora Online". PlantNET – The Plant Information Network System. 2.0. Sydney, Australia: The Royal Botanic Gardens and Domain Trust. Retrieved 13 Mar 2013.
  4. ^ F.A.Zich; B.P.M.Hyland; T.Whiffen; R.A.Kerrigan (2020). "Dysoxylum mollissimum subsp. molle". Australian Tropical Rainforest Plants Edition 8 (RFK8). Centre for Australian National Biodiversity Research (CANBR), Australian Government. Retrieved 6 June 2021.
  5. ^ a b Floyd, A. G. (2008). Rainforest Trees of Mainland South-eastern Australia (2nd, Revised ed.). Lismore, New South Wales: Terania Rainforest Publishing. p. 220. ISBN 978-0-958943-67-3. Retrieved 2010-02-01.
  6. ^ a b "Cedarworks - Red Bean". Archived from the original on 2010-07-28. Retrieved 2010-02-01.
  7. ^ Holzmeyer, Laura; Hauenschild, Frank; Mabberley, David J.; Muellner-Riehl, Alexandra N. (2021). "Confirmed polyphyly, generic recircumscription and typification of Dysoxylum (Meliaceae), with revised disposition of currently accepted species". Taxon. 70 (6): 1248–1272. doi:10.1002/tax.12591.
  8. ^ "Miva mahogany (Queensland Primary Industries and Fisheries)". Archived from the original on 2009-12-06. Retrieved 2010-02-01.
  9. ^ "Timber Health Hazards". U-Beaut Enterprises. 2014.