''Eucalyptus globulus'' subsp. ''bicostata'', commonly known as the southern blue gum, eurabbie, blue gum or Victorian blue gum, is a subspecies of tree that is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to south-eastern Australia. It has mostly smooth bark with some persistent slabs of old bark at the base, juvenile leaves with one

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), ...

side, glossy, lance-shaped adult leaves, warty flower buds in groups of three, white flowers and hemispherical to conical fruit. Eucalyptus bicostata - umbels

Description

''Eucalyptus globulus'' subsp. ''bicostata'' is a tree that typically grows to a height of and forms a

lignotuber A lignotuber is a woody swelling of the root crown possessed by some plants as a protection against destruction of the plant stem, such as by fire. Other woody plants may develop basal burls as a similar survival strategy, often as a respons ...

. The bark is mostly smooth, shedding in long strips to leave a white or greyish surface. There is sometimes rough, partially shed bark at the base of the trunk and ribbons of shedding bark in the upper branches. Young plants and

coppice Coppicing is the traditional method in woodland management of cutting down a tree to a tree stump, stump, which in many species encourages new Shoot (botany), shoots to grow from the stump or roots, thus ultimately regrowing the tree. A forest ...

regrowth have stems that are more or less square in cross-section, with a prominent wing on each corner. The juvenile leaves are

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

, arranged in opposite pairs, elliptic to egg-shaped, the lower surface covered by a white, waxy bloom, long and wide. Adult leaves are arranged alternately, glossy green, lance-shaped to curved, long and wide on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

long. The flower buds are arranged in groups of three in leaf

axil A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, fl ...

s on a thick peduncle long, the individual buds more or less sessile. Mature buds are glaucous, conical and warty, long and wide with two ribs along the sides and a flattened operculum that has a central knob. Flowering mainly occurs between January and March and the flowers are white. The fruit is a woody, sessile, hemispherical to conical capsule long and wide with two longitudinal ridges and the valves at about rim level.

Taxonomy and naming

Southern blue gum was first formally described by Joseph Henry Simmonds in the book ''Trees from other lands for shelter and timber in New Zealand: Eucalypts'' and given the name ''Eucalyptus bicostata''. In 1974, James Barrie Kirkpatrick reduced ''E. bicostata'' to the subspecies, ''E. globulus'' subsp. ''bicostata''. The change has been accepted by the

Australian Plant Census The Australian Plant Census (APC) provides an online interface to currently accepted, published, scientific names of the vascular flora of Australia, as one of the output interfaces of the national government Integrated Biodiversity Information Sys ...

. The epithet ''bicostata'' is derived from the Latin ''bicostatus'', "two-ribbed", referring to the buds and fruit.

Distribution and habitat

Southern blue gum grows in open forest in mountainous, largely inland country in New South Wales and Victoria. It is found between the Carrai National Park on the

Northern Tablelands The Northern Tablelands, also known as the New England Tableland, is a plateau and a region of the Great Dividing Range in northern New South Wales, Australia. It includes the New England Range, the narrow highlands area of the New England regio ...

of New South Wales and the ranges of eastern Victoria.

Gallery

References

{{Taxonbar, from1=Q21383457, from2=Q12839324 globulus Myrtales of Australia Flora of New South Wales Flora of Victoria (state) Plants described in 1927