flooded gum, rose gum, scrub gum
NZ Myrtaceae Key - Online edition
Eucalyptus grandis W.Hill
Common Names
Origin
Australia: coastal and subcoastal wet forests of eastern Australia, sporadically distributed from New South Wales to northern Queensland.
Cultivation
In New Zealand occasionally cultivated for timber or amenity; rarely naturalised from nearby specimens.
Distribution
In northern coastal and lowland areas of New Zealand.
Distinguishing Features
- A tall tree with smooth pale grey or white, powdery bark, with a persistent stocking of rough flaky greyish bark for up to four metres above the base.
- Mature leaves that are glossy, darker green on the upper side, paler beneath, strongly feather-veined.
- Flower buds that are stalkless or with a stalk to 5 mm long, ovate to club-shaped, green to yellow or sometimes glaucous, in clusters in 7–11.
- Capsules woody, funnel-shaped, stalkless or with a short stalk to 7 mm long, sometimes waxy grey-white, the 4 or 5 valves to rim level or projecting above the rim, broad-based and incurved.
Habit
Tall tree, occasionally to 70 m tall.
Bark and Stem/Trunk
Bark rough, flaky, greyish on basal 1–4 m of trunk, smooth above, powdery, pale grey or white; ribbons absent. Hairs and adventitious roots absent. Young stems square or rounded in cross-section.
Leaves
Mature leaves alternate, lanceolate, feather-veined, tip pointed, base tapering to stalk, blade glossy, dark green above and paler below, hairs absent, 80–180 mm long, 15–40 mm wide. Vein reticulation dense to very dense, oil glands inconspicuous. Main side-veins at a relatively wide angle to the midrib, intramarginal veins parallel to and just within margin; leaf stalk 10–25 mm long.
Juvenile leaves always stalked, opposite for few pairs then alternate, ovate, 40–140 mm long, 20–85 mm wide, base rounded or tapering to stalk, dark green above and paler below.
Flowers
Flowers in clusters of 7–11, clusters in leaf axils, stalk of cluster flattened, 10–18 mm long. Flower buds stalkless or with a stalk to 5 mm long; mature buds free, ovate to club-shaped (6–9 mm long, 4–5 mm wide), green to yellow or sometimes glaucous, bud cap conical or narrowly pointed; flowers (stamens) white; in mature open flowers, petals and sepals absent. Main flowering period: late summer to winter.
Fruit
Similar Species
- Eucalyptus saligna, Sydney blue gum, has similar leaves and buds, and smooth pale bark on the main trunk, with only a basal stocking of rough bark. However, the capsules may be cylindrical, cup-shaped or funnel-shaped, and have valve tips projecting above the rim of the capsule rather than broad-based and incurved. The buds and capsules of E. saligna are not glaucous.
- Eucalyptus botryoides, southern mahogany or bangalay, has generally similar leaves and buds, however, its buds have conical or hemispherical caps, and are usually stalkless or nearly so. The capsules are usually cylindrical to barrel-shaped, with valve tips ± level with capsule rim but not joined across the mouth of the capsule or incurved. The greatest difference is that E. botryoides has thick bark over the whole trunk to the large branches.
- Eucalyptus robusta, swamp mahogany or swamp messmate, has leaves and flower buds that are generally similar, but the buds are larger, to 24 × 8 mm, usually with a prominent stalk and long pointed cap, in clusters of 9–15, and the cylindrical woody capsules are also large, to 18 × 11 mm, with valve tips usually joined across the mouth of the capsule. The most conspicuous difference is that E. robusta has similar bark to E. botryoides, that is rough to the small branches.
Notes
Eucalyptus grandis var. ×grandiflora Maiden, considered as a variety of E. grandis for several decades, is now considered “A putative hybrid involving E. grandis and E. robusta”, and is not accepted by the Australian Plant Census (APC). We follow that decision.
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.