shining gum, silvertop
NZ Myrtaceae Key - Online edition
Eucalyptus nitens (H.Deane & Maiden) Maiden
Common Names
Origin
Australia: high country in New South Wales to north-eastern Victoria.
Cultivation
In New Zealand widely cultivated as shelter, forestry plantations, and in parks and gardens; occasionally naturalised from nearby planted specimens.
Distribution
Scattered records from throughout the North and South Islands of New Zealand.
Distinguishing Features
- A tree to 70 m tall with more or less smooth bark or with a thin stocking of rough grey bark on the base; the smooth bark predominantly pale grey to greenish-grey but with patches of white, cream or pale brown. Ribbons often present in the crown of the tree.
- Young stems square in cross-section and prominently winged; may be waxy grey-white.
- Adult leaves alternate, glossy, green, long, to 300 mm long and 40 mm wide, same colour above and below, intramarginal vein parallel to and well removed from margin (sometimes doubled, the outer being close to margin and less prominent), oil glands usually obscure.
- Juvenile leaves that are usually blue-green or waxy grey-white, opposite and stalkless for many pairs until sapling stage, ovate to lanceolate, sometimes to 180 mm long and 95 mm wide, stem-clasping, apex pointed. Coppice growth, with juvenile leaves, is conspicuous.
- Flowers in clusters of 7, in leaf axils, stalk of cluster angular to somewhat flattened, to 15 mm long. Mature buds stubby, stalkless, oblong to ovate, to 7 mm long and 4 mm wide, green and pink, often slightly angled longitudinally, bud cap conical, flowers white.
- Fruit a stalkless woody capsule, cup-shaped to barrel-shaped, to 7 mm long and 7 mm wide, faintly angled longitudinally, disc descending below the capsule rim, valves 3 or 4, slightly projecting above the rim or near rim level.
Habit
Tree to 70 m tall.
Bark and Stem/Trunk
Bark smooth throughout or with a thin stocking of rough grey bark on basal 1 m of trunk; smooth bark predominantly pale grey to greenish-grey but with patches of white, cream or pale brown, with horizontal black scars sometimes present; ribbons often present in the crown of the tree. Hairs and adventitious roots absent. Young stems square in cross-section and prominently winged; may be waxy grey-white.
Leaves
Adult leaves alternate, stalked, blade lanceolate to sickle-shaped, 100–300 mm long, 15–40 mm wide, base tapering to stalk, margin smooth, glossy, green, same colour above and below, hairless; side-veins at an angle greater than 45° to midrib, vein reticulation moderate to dense, intramarginal vein parallel to and well removed from margin (sometimes doubled, the outer being close to margin and less prominent), oil glands usually obscure; leaf stalk 10–40 mm long.
Juvenile leaves opposite and stalkless for many pairs (until sapling stage), ovate to lanceolate, 65–110(–180) mm long, 28–55(–95) mm wide, stem-clasping, apex pointed, usually blue-green or waxy grey-white.
Flowers
Flowers in clusters of 7, in leaf axils, stalk of cluster angular to somewhat flattened, 5–15 mm long. Mature buds free, oblong to ovate, 6–7 mm long, 3–4 mm wide, green and pink, often slightly angled longitudinally, bud cap conical, flowers (stamens) white; in mature open flowers, petals and sepals absent. Main flowering period: summer to early autumn.
Fruit
Similar Species
Eucalyptus nitens belongs in a group of eucalypts having juvenile leaves that are large, stalkless, waxy grey-white or not, opposite for many pairs on square, winged stems, small buds in clusters of seven and small fruit with descending disc.
Closely related to E. denticulata, it differs in the less conspicuous, wider juvenile leaves, the longer period of juvenility, and the smooth margins of the adult leaves. The buds of E. denticulata do not shed the outer bud cap as in E. nitens but have an indefinite “scarring” only at the tip.
The bark and leaves are very similar to E. globulus, but the two species differ greatly in the size and shape of the flower buds and capsules.
Notes
In situations where both E. nitens and E. denticulata occur near each other, there is some intergradation. In E. denticulata the juvenile stage is less prolonged, the adult leaves are toothed along the edges with lenticels (pores on the leaf margins) whereas in E. nitens the leaves are smooth-edged, and the outer bud cap does not shed as a whole cone but appears to be persistent with a reduced, somewhat deformed, inner bud cap at the tip (outer bud cap completely shed leaving a bud cap scar in E. nitens).
Eucalyptus is a genus of nearly 800 species, most of which are endemic to Australia, with a few species extending to parts of Malesia and as far north as the Philippines.