Eucalyptus coolabah Blakely & Jacobs
Voucher: JAB100, JAB107, JAB133, JAB137 Previously known in its southern distribution as E. microtheca
Family: Myrtaceae. Common name(s): Coolabah.
Habit: Tree to 20 m tall. Distribution: Widespread in arid and semi-arid Australia.
General features: Density 900-1100 kg/m3. Heartwood reddish brown and darker than sapwood.
Vessels Tangential vessel diameter: range 11-117 µm; mean 61 µm; SD 22 µm; average maximum 32-98 µm; n = 864 vessels. Vessels per square millimetre: range 19-130 vessels per mm2; n = 22 sampled areas. Vessels solitary. Perforation plates simple without prominent rim. Heartwood vessels with tyloses. White deposits may be present in heartwood vessels. Vessel to vessel pits with vestured pits.
*Fibres/tracheids With numerous, distinctly bordered pits present.
Axial parenchyma Axial parenchyma apotracheal and paratracheal. Apotracheal axial parenchyma diffuse to diffuse-in-aggregate. Paratracheal parenchyma scanty to vasicentric.
Rays Rays 1-(1) 2 cells wide with uniseriate rays very common to exclusive (n = 529 rays). Rays of uniform width and not wider than vessels. Rays 11-28 per tangential mm (n = 19 sampled areas). Ray height: range 46-335 µm; mean 118 µm; SD 42 µm; n = 322 rays.
Helical thickenings Absent.
Physical and chemical tests: Chrome azurol-s test negative. Heartwood fluorescence present or absent. Froth test weakly positive to positive. Ethanol extract fluorescence absent. Ethanol extract discoloured. Water extract discoloured. Water extract fluorescence absent.
Aboriginal Spear; fire-making apparatus; message sticks; coolamons (wooden dish); throwing sticks (Johnston & Cleland 1943); unspecified heavy ornaments (Latz 1995); emu decoy horn; digging bowl (Kamminga 2002); water is obtained from rootwood (Mitchell & Wilcox 1994)
European Fence posts (Mitchell & Wilcox 1994); historically it has been used for buildings; possibly cabinet work; railways (Maiden 1889)
Notes: Absence of tyloses is not diagnostic and their presence is recorded only where they are abundant in heartwood (IAWA 1989: 261).
* At this stage the key makes no distinction between fibres and tracheids as they are difficult to tell apart and there is some confusion in the wood anatomical literature as to their definitions in hardwoods (IAWA: 264). For example, the taxa for which this character was predominantly included - Myrtaceae A (Eucalyptus & Melaleuca) - contain numerous, conspicuous bordered pits that are both called fibre tracheids (Dadswell 1972: 21) and vasicentric tracheids (IAWA: 262).