Eucalyptus subulata Cunn. ex Schauer

Eucalyptus tereticornis is a tree up to 45 m tall or taller; trunk erect, 1-1.8 m in diameter; crown large, open or fairly dense, variable; bark smooth, whitish, peeling in irregular thin sheets or large flakes, becoming mottled with white, grey or bluish patches, often some rough, dark grey bark at base; twigs reddish or yellowish-green. Leaves alternate, drooping on slender leaf stalks, narrowly lance shaped, 10-21 x 12-25 mm, often curved, long pointed at tip and short pointed at base, slightly thickened, shiny green on both surfaces, hairless, with many fine side veins at an angle and a distinct vein along edge; juvenile leaves opposite for 2-3 pairs, with slender leaf stalks, elliptic to broadly lance shaped, 6-16 cm long, 5-6 cm wide, green. Flower clusters (umbel) single at leaf base, 2.5-3 cm long including rounded stalk of 1 cm; flowers 5-12, spreading on equal stalks 5-7 mm; buds 12-16 x 5 mm, with half-rounded base and long, narrow, conical, hornlike lid. Fruit or seed capsules several, half round or top shaped, 6-9 mm long, 8-10 mm in diameter, with raised disc and prominent rim, opening with 4-5 raised teeth curving inward; seeds many, tiny, 1 mm long and broad, shiny, dark brown to black. The genus Eucalyptus was described and named in 1788 by the French botanist l’Héritier. The flowers of the various Eucalyptus species are protected by an operculum, hence the generic name, which comes from the Greek words ‘eu’ (well), and ‘calyptos’ (covered). The specific name ‘tereticornis’ is a Latin word meaning ‘long’, ‘round’ and ‘horn’, and refers to the very long, hornlike lid (operculum) of the flower bud.

In plantations E. tereticornis begins to produce seed 3-6 years after establishment.

Will grow on a variety of soils, with a preference for deep, well-drained soils of fairly light texture, including alluvial soils, silts and clays. A neutral or slightly acidic pH is suitable, but not a strongly acidic one.

E. tereticornis has the widest latitudinal distribution of any species in the genus. It occurs over a wide range of climatic conditions, and principally in open-forest formation with a number of other eucalypts and on river flats or hill slopes with alluvial or sandy to gravelly soils. E. tereticornis has been most successful in summer rainfall conditions with a moderate to fairly severe dry season. It is considerably drought resistant but is susceptible to frost. The species tolerates occasional waterlogging. In many countries, among the Eucalyptus species, E. tereticornis is considered relatively fire resistant.

Indigenous to Papua New Guinea and Australia, E. tereticornis was introduced to a number of tropical or subtropical countries in the latter half of the 19th and the 1st half of the 20th centuries. It was introduced in Ethiopia in 1865, in Pakistan in 1867, in Zimbabwe in 1900, in the Philippines in 1910, and in India in 1919. Together with the landrace variously known as ‘Mysore gum’, ‘Mysore hybrid’ or ‘Eucalyptus hybrid’, E. tereticornis accounted for 415 000 ha out of the total area of Eucalyptus trees reported as planted in India by 1974.

Germination is good and uniform, 30-70%; completed in 14-30 days. No pretreatment is required. Vegetative propagation has been carried out successfully from ligno-tuberous tissue, from branch cuttings from 2- to 3-year-old saplings, and from epicormic shoots from older trees. In Congo, 60% rooting success has been obtained from cuttings.

The species coppices vigorously: a 99% rate has been reported from Congo. Rotation varies with site quality and the objects of management. In Congo, for example, the rotation is 5-7 years, and in Argentina it is 9-12 years with a single thinning at about 7-8 years.

In general, E. tereticornis has proved fairly free of pests and diseases. In many areas termites attack young plants if insecticide is not used while planting. In India, the most serious disease has been the canker caused by the fungus Corticium salmonicolo.

Seed storage behaviour is orthodox. Viability can be maintained for several years in hermetic storage at 3 deg. C with 6-10% mc. A germination rate of 8% following 10 years of open storage at room temperature has been reported. There are approximately 320 000-600 000 viable seeds/kg.

Shade or shelter: Planted in shelter-belts as a windbreak and for shade. Reclamation: A suitable species in reforestation programmes.

Apiculture: E. tereticornis is a major source of pollen and nectar, producing a caramel-flavoured honey. Fuel: E. tereticornis is popular and widely used for firewood and charcoal. Fibre: In India, the most important use of E. tereticornis is for its good quality pulp and paper. The strength properties of the paper improve after the tree reaches 9 years of age, but the dark colour of the heartwood, in comparison with some other Eucalyptus species, is a disadvantage. It is also used for hardboard, fibreboard and particleboard. Timber: The wood is red, hard, heavy, strong, durable, uniform in texture and has an interlocked grain. In Australia the wood is one of the types most resistant to marine borer and is widely used as a construction and mining timber. It is also used for poles, stakes, boxwoods, bridge timber, railway sleepers and wharves. It is suitable for posts of all sizes. Tannin or dyestuff: The wood contains 6-12% tannin, and the bark 3-15. In Congo, tannin is extracted from the wood and the bark. Essential oil: The leaves are 1 of the sources of eucalypt oil, and the principal leaf oil is cineole (45%). The oil yield percentage by fresh weight is 0.9-1.4%. The wood contains 0.5% essential oil. Oil extraction is common in the Philippines.