Dipodium variegatum

Dipodium variegatum
flowering in Meroo National Park
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Cymbidieae
Genus: Dipodium
Species: D. variegatum
Binomial name
Dipodium variegatum
M.L.Clem & D.L. Jones[1][2]

Dipodium variegatum, commonly known as blotched hyacinth-orchid[1] or slender hyacinth-orchid,[3] is a leafless mycoheterotrophic orchid that is endemic to south-eastern Australia. It forms mycorrhizal relationships with fungi of the genus Russula.

Description

For most of the year, plants are dormant and have no above-ground presence. Below the ground lie fleshy roots. Flower spikes between 30 and 60 cm in height appear between August and February.[3] These racemose inflorescences have 2 to 50 cream to light green fleshy flowers with maroon blotches. The sepals and petals are slightly recurved and the three-lobed labellum is maroon or mauve with mauve hairs.[4] A form with tepals and petals that are completely dark maroon is found in Tallebudgera in Queensland.[3]

This species may be distinguished from others in the genus by spots on both the pedicels and ovaries.[5]

Taxonomy

The species was formally described in 1987 by Australian botanists Mark Clements and David Lloyd Jones. The type specimen was collected beside the Pacific Highway in Beenleigh, Queensland.[1]

Distribution and habitat

Dipodium variegatum occurs in the states of Queensland, New South Wales and Victoria.[4]

Ecology

DNA recovered show it forms mycorrhizal associations with Russula solaris and R. occidentalis, in keeping with the observation that many members of the genus form relationships with fungi of the family Russulaceae.[6] The orchid has been observed to occur in close proximity to Eucalyptus species and it is thought that a relationship exists with these trees through this mycorrhizal association.[7]

Pollination of this species, as for all species in the genus, is by native bees and wasps.[3]

Conservation

Immature fruit

The species is listed as "rare" on the Victorian Department of Environment and Primary Industries' advisory list of rare or threatened plants in Victoria [8]

Cultivation

No leafless species of Dipodium has been sustained in cultivation due to the inability to replicate its association with mycorrhizal fungi in a horticultural context..[3]

References

  1. 1 2 3 "Dipodium variegatum". Australian Plant Name Index (APNI), IBIS database. Centre for Plant Biodiversity Research, Australian Government. Retrieved 23 January 2014.
  2. "Dipodium variegatum M.A.Clem. & D.L.Jones". The Plant List version 1.1. Retrieved 23 January 2013.
  3. 1 2 3 4 5 Jones, David L. (2006). A complete guide to native orchids of Australia, including the island territories. Australia: Reed New Holland Publishers. ISBN 9781877069123.
  4. 1 2 Weston, P.H. "Dipodium variegatum M.A.Clem. & D.L.Jones". PlantNET - New South Wales Flora Online. Royal Botanic Gardens & Domain Trust, Sydney Australia. Retrieved 23 January 2014.
  5. Weston, P.H. "Dipodium". PlantNET - New South Wales Flora Online. Royal Botanic Gardens & Domain Trust, Sydney Australia. Retrieved 23 January 2014.
  6. Dearnaley, J.D.W. (2006). "Fungal Endophytes in Australian Myco-heterotrophic Orchids" (PDF). 8th International Mycological Congress. Retrieved 25 January 2014.
  7. Bougoure, J.J.; Dearnley, J.D.W. "The Fungal Endophytes of Dipodium variegatum (Orchidaceae)" (PDF). Australian Mycologist. Retrieved 26 January 2014.
  8. "Threatened species advisory lists". Department of Environment and Primary Industies. Retrieved 23 January 2014.
This article is issued from Wikipedia - version of the 2/24/2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.