Corymbia opaca, also known as desert bloodwood, is a species of tree that is Endemism to northern Australia. It has rough bark on part or all of the trunk, lance-shaped leaves, club-shaped flower buds and urn-shaped fruit. Several parts of this plant are used by Aboriginal Australians in traditional medicine.
Description
Corymbia opaca is a tree, rarely a mallee, that typically grows to a height of and forms a
lignotuber. It has rough, tessellated, reddish brown bark over some or all of its trunk. Young plants and
coppice regrowth have petiolate, egg-shaped to lance-shaped leaves, long and wide, with a small point on the tip. Adult leaves are arranged alternately, the same shade of green or greyish green on both sides, lance-shaped, long and wide with a petiole long. The flower buds are arranged in groups of seven on an unbranched, cylindrical peduncle long, the individual buds on pedicels long. Mature buds are club-shaped, with an oval
Hypanthium about long and wide and a saucer-shaped operculum that has a central point and is about long and wide. The flowers are creamy white and the fruit is an urn-shaped capsule long and wide.
Taxonomy and naming
The desert bloodwood was first formally described in 1985 by Denis John Carr and Stella Grace Maisie Carr who gave it the name
Eucalyptus opaca and published the description in their book
Eucalyptus 1 - New or little-known species of the Corymbosae.
The type specimens were collected in 1983 from the
Lasseter Highway near
Kata Tjuta. In 1995, Ken Hill and Lawrie Johnson changed the name to
Corymbia opaca, publishing the change in the journal
Telopea.
[Philip Moore 2005 “A Guide to Plants of Inland Australia” Reed New Holland] The
Botanical name (
opaca) is derived from the
Latin word
opacus meaning "darkened, dull, not shining or opaque".
Some authors and herbaria accept C. opaca as a distinct species and others consider it to be inseparable from C. terminalis and C. tumescens.
Distribution and habitat
Corymbia opaca occurs in scattered population in desert areas of the southwest Kimberley,
Pilbara and northern desert regions of Western Australia, in central and southern parts of the Northern Territory (particularly around
Alice Springs) and in the
Mann Ranges and
Musgrave Ranges in the far northwest of South Australia. It commonly grows in sandy soils in alluvial areas and on lower hillslopes.
[Purdie. J., Materne. C., Bubb. A, 2008 “A Field Guide to Plants of the Barkly Region of the Northern Territory” Barkly Landcare and Conservation Association Incorporated]
Conservation status
This eucalypt is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife and as "least concern" in South Australia.
Use in bush medicine
Occasionally a bloodwood tree will shed a piece of bark, hence opening a "wound" through which a blood-like kino will flow. The sap flows until it crystallises, covering up the hole in the bark. Australian Aboriginals collect this substance as
bush medicine. They apply the sticky gum directly to sores or cuts and it works as an antiseptic. If the sap is in a dried form, it can be crushed into powder and boiled in water to use as an antiseptic wash.
Another use of the bloodwood sap by Aboriginal people is to tan "kangaroo-skin waterbags".
People collect (a type of bush tucker) from the tree, which are produced by an insect in gall.
The roots of the bloodwood tree store water. Aboriginal peoples would dig up the roots and drain the water into a container.
See also
