Australian Tropical Rainforest Plants - Online edition

Syzygium macilwraithianum B.Hyland

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Leaves and flowers [not vouchered]. © G. Sankowsky
Leaves and fruit. © CSIRO
Fruit, side views and transverse section. © W. T. Cooper
Scale bar 10mm. © CSIRO
Habit, flower & bud, anther, fruit, seedling. © CSIRO
10th leaf stage. © CSIRO
Cotyledon stage, hypogeal germination. © CSIRO

Hyland, B.P.M. (1983) Australian Journal of Botany Supplementary Series 9: 99. Type: B. Hyland 2643 RFK, Timber Reserve 14, Leo Creek, 19.ix.1972 (holotypus QRS).

Common name

MacIlwraith Range Bark in the Wood; MacIlwraith Satinash


Sections of bark included in the wood. Blaze somewhat sticky and the outer and inner blazes distinct.


Oil dots generally sparsely distributed. Midrib slightly raised or flush with the upper surface of the leaf blade. Leaf blades about 4-7 x 2-4 cm. Petioles about 0.2-0.4 cm long.


Bracts deciduous, absent at anthesis. Buds very characteristic, apex hemispherical, with calyx lobes forming four peripheral lobes, tube (hypanthium) +/- campanulate, but swollen at the base and contracted in the middle, calyx tube (hypanthium) + pedicel about 6-7 mm long, calyx tube (hypanthium) slightly ribbed, about 4-6 mm diam., calyx lobes uniform, concave, +/- triangular, about 2-3 mm long. Petals +/- orbicular, concave, about 5-6 mm diam., oil dots visible, about 100 or more per petal. Outer staminal filaments about 6-9 mm long, anthers about 0.7-0.9 x 0.6-0.7 mm, gland not visible or gland small, inconspicuous, terminal, near the back of the anther. Ovules about 17-22 per locule, placentas central, ovules radiating, ascending. Style about 9-11 mm long, approximating the stamens.


Fruits depressed globular, attaining about 20-30 x 30-40 mm, calyx lobes persistent, about 2-3 mm long, pericarp succulent. Seed solitary, about 10-15 x 20-25 mm, testa adhering to the pericarp and also to the rugose surface of the cotyledons by means of peg-like intrusions, cotyledon texture variable, the peripheral layer being +/- ruminate while the more central section is marked by large, conspicuous, spherical glands, attaining about 1 mm or more diam. Radicle central, cotyledonary stipules present.


Cataphylls about 3 or 4 pairs. At the tenth leaf stage: leaf blade elliptic or elliptic-obovate, apex acute, base cuneate or attenuate, glabrous; oil dots scattered, visible with a lens. Seed germination time 16 to 298 days.

Distribution and Ecology

Endemic to CYP, known only from the Iron Range and McIlwraith Range areas. Altitudinal range from 50-600 m. Grows in well developed rain forest on a variety of sites but is more abundant in upland situations.

Natural History & Notes

This species has no commercial value at present and it is unlikely to produce millable logs as sections of bark are included in the wood. Wood specific gravity 0.75. Hyland (1983).

RFK Code
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