Eucalyptus tereticornis

A large tree growing to 50 m, forming a lignotuber.

This species is has a large natural distribution. In NSW, it grows mainly in the coastal subdivisions but extends into the tablelands, with some scattered records in the western slopes; as far south as around Bega, but then found in Victoria where a disjunct population grows between Lakes Entrance and Traralgon and to the north of Lake Glenmaggie. It is found more or less continuously northwards up the NSW coastal and tablelands into Queensland, where it again extends more or less continuously to the start of the Cape York Peninsula. It is also found in New Guinea.

In NSW, it forms a dominant part of dry sclerophyll forests and woodlands, usually on heavier soils – clay and alluvium. E. tereticornis is one of the key canopy species of the threatened Cumberland Plain Woodlands in Sydney and also forms a dominant species in many other vegetation communities.

The trunk is straight, usually unbranched for more than half of the total height of the tree and can have a trunk of up to 1 metre or more wide. The limbs are unusually steeply inclined for a Eucalyptus species. Bark is shed in irregular sheets, resulting in a smooth trunk surface coloured in patches of white, grey and blue, corresponding to areas that shed their bark at different times. It usually has some plates of brown bark at the base, sometimes short, sometimes extending up several metres in a non-uniform pattern.

Eucalyptus spp. have simple and usually alternate adult leaves with juvenile leaves starting off opposite to alternate (disjunct). In this species, juvenile foliage / coppice regrowth is dull bluish-green, ovate or broadly-ovate leaves, to 130 mm long and to 80 mm wide, blue-green in colour. Adult leaves are the same shade of green to blue-green on both sides, lanceolate to falcate, to 220 mm long and to 35 mm wide, tapering at the base to a petiole to 30 mm long.

The primary inflorescence of “eucalypts” (Angophora / Corymbia / Eucalyptus) is an umbellaster (an umbel-like cluster of flowers). In the flowers of Corymbia and Eucalyptus, the petals and sepals are fused into the distinctive calyptra / operculum (bud cap) which is shed when the flower opens (in some species, 2 bud caps (opercula) are shed). The flowers are conspicuously staminate – where many stamens are basically taking over the role of the petals, all surrounding one central carpel. In this species, the flower buds are arranged in leaf axils, usually in groups of seven, but sometimes 9 to 11, the individual buds on pedicels to 6 mm long.

Mature buds are an elongated-oval shape, to about 15 mm long and to 6 mm wide with a conical to horn-shaped operculum / calyptra that is much longer than the floral cup. Flowering has been recorded in most months and the flowers are white.

The fruit of eucalypts are a woody capsule (commonly called ‘gum nuts’) which come in a wide variety of shapes with the top part having a sunken, flat or raised disc and with the valves inserted, disc-level, exserted to strongly exserted. In this species, the capsules are to 6 mm long and to 8 mm wide with the valves prominently protruding and with a raised disc. Seeds usually black, 0.8–1.5 mm long.