blue gum, forest red gum, red gum, red iron gum
NZ Myrtaceae Key - Online edition
Eucalyptus tereticornis Sm. subsp. tereticornis
Common Names
Origin
Australia: widespread in eastern Australia and possibly southern New Guinea. Reported to have the greatest latitudinal range of all eucalypts.
Cultivation
In New Zealand almost exclusively in cultivation, and occasional in parks, tree collections and plantation trials; rare possible naturalisations from nearby trees.
Distribution
Mainly from Northland to Waikato, and Hawkes Bay in the North Island, and rarely in the South Island of New Zealand.
Distinguishing Features
- A tall tree to 50 m with smooth bark throughout that is mottled white, cream, yellow, pink and grey; sometimes with persistent dark grey flakes of rough bark on base of large trunks. Young stems usually square in cross-section and prominently winged.
- Adult leaves dull or glossy green, same colour above and below, alternate, lanceolate to sickle-shaped, side-veins at an angle greater than 45° to midrib.
- Juvenile leaves that are dull, blue-green or green, broadly ovate, to 130 mm long and 80 mm wide, always stalked, opposite for 5–8 nodes then alternate.
- Flowers in clusters of 7, 9 or 11, in leaf axils, mature buds that are elongated, with a very distinctive long, narrow, horn-shaped cap to 22 mm long, that is often swollen at the base, cap longer than the base of the bud, flowers white or very rarely pink.
- Fruit a small, stalked, woody capsule with disc broad and steeply rising above the capsule rim, valves 4 or 5, strongly projecting above the rim.
Habit
Tree to 50 m tall.
Bark and Stem/Trunk
Bark smooth throughout, shedding in large plates or flakes, to leave the surface mottled white, cream, yellow, pink and grey; sometimes with persistent dark grey flakes of rough bark on base of large trunks; ribbons absent. Hairs and adventitious roots absent. Young stems usually square in cross-section and prominently winged.
Leaves
Adult leaves alternate, stalked, blade lanceolate to sickle-shaped, 80–220 mm long, 10–35 mm wide, base tapering to leaf stalk, dull or glossy, green, same colour above and below, hairless; side-veins at an angle greater than 45° to midrib, vein reticulation sparse to moderate, intramarginal vein parallel to and just within margin or well removed from it (sometimes double), oil glands present; leaf stalk 13–30 mm long.
Juvenile leaves always stalked, opposite for 5–8 nodes then alternate, broadly ovate, 60–130 mm long, 30–80 mm wide, dull, blue-green or green.
Flowers
Flowers in clusters of 7, 9 or 11, in leaf axils, stalk of cluster angular, 7–25 mm long. Mature buds free, stalked, stalks 2–6 mm long; elongated ovate (9–16 mm long, 3–6 mm wide), the bottom part of the bud short, green to creamy, the cap conical to horn-shaped (8–22 mm long), flowers (stamens) white or very rarely pink; in mature open flowers, petals and sepals absent. Main flowering period: may occur most months of the year.
Fruit
Similar Species
Notes
Four subspecies of Eucalyptus tereticornis have been described in Australia, two with limited distribution. The subspecies vary mostly on bud shape. New Zealand records have generally not been determined to subspecies, but the majority of the collections at the National Forestry Herbarium belong to E. tereticornis subsp. tereticornis with a few specimens of E. tereticornis subsp. mediana also recorded. Eucalyptus tereticornis subsp. tereticornis possesses a horn-shaped cap dilated at its base and 4–7 times the length of base of the bud. In E. tereticornis subsp. mediana the shorter, fatter buds possess a broadly conical cap operculum that is not basally dilated and 2–4 times length of base of the bud.
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.