pronounced: kor-RIM-bee-uh pol-ee-KAR-puh
pronounced: yoo-kuh-LIP-tuss pol-ee-KAR-puh
Corymbia is from the Greek κορυμβος (korymbos), a cluster, referring to the way the plant bears the flowers; polycarpa is from πολυς (polys), much, many, great, and καρπος (karpos), fruit.
This is one of the dominant gum species on Magnetic Island, and can grow to 25 m. The fine specimen in the photograph is in the grounds of the old school at Picnic Bay. The bark is tessellated, flaky, persistent throughout, grey to pale brown. There are both pith glands and bark glands present. It grows on hills, slopes and flats, but prefers sandy soils.
The juvenile leaves are elliptic to lanceolate, 5 – 8 cm by 2 – 2.5 cm, while the coarse adult leaves are 10 – 20 cm by 1 – 3 cm. The lateral veins are obscure, obtuse, closely spaced. The intramarginal vein is distinct and continuous.
The flowers are creamy white, up to 2 cm in diameter, compound, terminal, and appear from December to June.
The fruits are urn-shaped, borne on a pedicel, with 4 chambers. They are 18 – 35 mm long, and 11 – 16 mm in diameter The disk is depressed, and the valves enclosed. The seeds are regular and laterally compressed, boat-shaped or ovoid, shallowly veined, dull to semi-glossy, red-brown.
The sapwood is a pale pink to a light brown, and the heartwood dark brown, often with an abundance of kino veins. It is a very durable timber, with an above-ground life expectancy of over 40 years, and an in-ground expectancy of over 25 years. Untreated sapwood is susceptible to lyctine borer attack, and the timber is not resistant to termites. It is regarded as a hardwood, and is not very easily worked with hand tools. Because of the kino veins, it is generally used as round timber rather than sawn timber. It has been used as poles, piles, railway sleepers and mining timbers, for fencing and house stumps.
Aborigines used the gum medicinally.