Eucalyptus nitens (Deane et Maiden) Maiden

Eucalyptus nitens is a tall forest tree, commonly 40-70 m in height and occasionally up to 90 m, with a diameter at breast height of 1-2 m or more; typically has a good shape and a straight bole, which may be 1/2 or 2/3 of the tree height; bark smooth throughout, greyish, decorticating in long ribbons, sometimes with a relatively thin basal stocking of rough bark for a few metres; saplings and young trees characteristically green barked. Leaves of seedlings and juvenile trees are opposite, sessile, amplexicaul, ovate, glaucous, bluish, discolourous; seedlings 4-10 x 2-4 cm, juveniles 8.5-17 x 4.5-8 cm; adult leaves alternate, petiolate, lanceolate to narrow-lanceolate, 13-24 x 1.5-2.5 cm, green, concolorous. Inflorescence simple, axillary, 7 flowered; peduncles angular to somewhat flattened; pedicles usually absent, occasionally very short; buds cylindrical or ovoid, often angular or ribbed, 6-7 x 3 mm; opercula conical. Fruits sessile, ovoid, often fairly ribbed, 4-7 x 4-6 mm, with a glossy surface; disk narrow, descending; valves 3 or 4, about rim level or slightly exserted. 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). ‘Nitens’ is a Latin word for ‘shining’, ‘polished’ or ‘bright’, and refers to the leaves, buds, fruits and bark. The fruits in particular have a distinctive, glossy, varnished appearance.

A high degree of selfing is suspected. E. nitens is a late and light seed producer.

Best growth is on well-drained, deep, rich, moist loamy soils over clay, but it will grow satisfactorily on a wide range of moderately fertile soils.

E. nitens occurs in the hills and valleys in mountain areas, sometimes as small pure stands and often forming part of a mosaic of Eucalyptus species. In its natural habitat, the climate is cool to warm, or humid to subhumid, with the mild summers rarely having very high temperatures. It is one of the most frost-tolerant of the fast-growing commercial Eucalyptus species and is moderately drought resistant.

E. nitens is a notoriously shy seeder, and seed collections tend to be concentrated on the occasional trees that carry seed. It handles well in nurseries, tolerates root pruning and can be bare-root planted in a suitable climate.

E. nitens is an evergreen, fast-growing tree with very good vigour and volume growth. The lower branches of trees on young plantations tend to stand out at right angles to the trunk and do not shed as well as those of most Eucalyptus species. E. nitens can be coppiced. It is very sensitive to fire and is killed even by light wild fire. But if sufficient seed is available, the regeneration is prolific, and regrowth develops rapidly on the resulting ash beds. It is estimated that E. globulus and E. nitens can grow at 40 cubic m/ha per year. Rotations of 8-10 years are envisaged for pulpwood production, and up to 25 years for timber production.

The juvenile leaves of E. nitens are unpalatable to many pests, in some cases even to the leaf-cutting atta ants of Brazil and to the Australian opossums that in New Zealand eat the foliage. The pests attack the adult leaves.

Seed storage behaviour is orthodox. Hermetic storage at 4-6% mc and subzero temperatures is recommended. There are approximately 260 000 viable seeds/kg.

Fuel: A suitable fuelwood, and is popular for this in New Zealand. Fibre: Wood from E. nitens is widely used for pulp and paper. Timber: The heartwood is straw coloured or pale pink, straight grained, tough but relatively easy to work, and not durable. It has a density of 670-720 kg/cubic m. It is used for general building construction, flooring, joinery, panelling and furniture. The wood is suitable for sawing and is used for general construction and, in a round form, for building and transmission poles. Essential oil: The essential oil from E. nitens is monoterpenoid in nature and is characterized by large amounts of alpha-pinene (10-17%) and 1,8-cineole (18-70%), the latter being a principle constituent of medicinal oils.