Eucalyptus imlayensis
Encyclopedia
Eucalyptus imlayensis, the Mount Imlay Mallee is a eucalyptus
plant. It is endemic to the far south east of New South Wales
, only occurring near the summit of Mount Imlay
.
in appearance, growing to 7 metres tall. Bark is smooth, though it sheds in ribbons, curling over near the base. Bark is green when fresh, aging to orange, brown then grey. Juvenile leaves are ovate, without stalks. Sometimes slightly toothed. Adult leaves are quite thick, veiny, straight or curved, 15 cm by 2 cm. The same glossy green above as below the leaf. Leaves held fairly erect. Cream or white flowers form in threes, though the flowering period is not recorded. Gumnuts are stalk-less or practically so, on a flattened stem. The disc surrounding the gumnut is prominent. The stems of seedlings are square in cross section, "winged" at the edges.
on the coast is 866 mm. However, the rainfall on the mountain would be considerably higher. Mountain mists add extra moisture to the habitat. The soils are poor in nutrient, based from sandstone
and conglomerate
rocks. These sedimentary rocks are from the Devonian
period, laid down 395 to 345 million years ago. Part of the Merimbula group placed above Ordovician
sediments.
Nearby species include the rare Imlay Boronia
, also only found on this mountain. Other nearby plants include Tea Tree
, Devil's Twine
, Digger's Speedwell, Tasmanian Flax-lily
, Rasp Fern
, Spiny-head Mat-rush
, Scented Paperbark
, Common Shaggy Pea
, Narrow-leaved Peppermint
and Blotchy Mint-bush.
The Imlay Mallee has probably adapted to the relatively high levels of rainfall, mountain mist, and occasional fires
. It is suggested that changes to the micro habitat may be hazardous to the plant's survival.
of this species was collected in May 1979. The specific epithet imlayensis is named after Mount Imlay. This plant was placed in the Eucalyptus genus. Within the subgenus Symphyomyrtus, the section Maidenaria, the series Johnstonianae and the subseries Imlayensosae. This isolated species appears to be related to the eucalyptus plants of Tasmania
.
is a possible cause for the deaths of individual Imlay Mallees in recent times, as is insect attack and drought. Galls on leaves have been observed, caused by an unknown psyllid. Despite the requirement of fires to promote seed germination and new growth in many eucalyptus species, it is not considered advisable to burn this area.
The population of this species consists of around 80 mature plants, with no juveniles. Natural regeneration seldom occurs, though the tree may re-sprout from the base after fire. In recent years the population has declined
, and the Imlay Mallee is now considered critically endangered
by extinction
in New South Wales.
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
plant. It is endemic to the far south east of New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, only occurring near the summit of Mount Imlay
Mount Imlay National Park
Mount Imlay is a national park in New South Wales , 387 km south of Sydney, named after the Imlay brothers, who were early pioneers to the district. It is accessed from the Princes Highway, south of Eden, New South Wales....
.
Description
A typical malleeMallee (habit)
Mallee is the growth habit of certain eucalypt species that grow with multiple stems springing from an underground lignotuber, usually to a height of no more than ten metres...
in appearance, growing to 7 metres tall. Bark is smooth, though it sheds in ribbons, curling over near the base. Bark is green when fresh, aging to orange, brown then grey. Juvenile leaves are ovate, without stalks. Sometimes slightly toothed. Adult leaves are quite thick, veiny, straight or curved, 15 cm by 2 cm. The same glossy green above as below the leaf. Leaves held fairly erect. Cream or white flowers form in threes, though the flowering period is not recorded. Gumnuts are stalk-less or practically so, on a flattened stem. The disc surrounding the gumnut is prominent. The stems of seedlings are square in cross section, "winged" at the edges.
Habitat
This small eucalyptus occurs on a rocky slope, near the mountain's summit. Growing as a multi-stemmed mallee, surrounded by low heathland plants on mossy ground. Average annual rainfall at EdenEden, New South Wales
Eden is a coastal town in the South Coast region of New South Wales, Australia. The town, south of the state capital Sydney near the border with Victoria, is located between Nullica Bay to the south and Calle Calle Bay, the northern reach of Twofold Bay, and built on undulating land adjacent to a...
on the coast is 866 mm. However, the rainfall on the mountain would be considerably higher. Mountain mists add extra moisture to the habitat. The soils are poor in nutrient, based from sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
and conglomerate
Conglomerate (geology)
A conglomerate is a rock consisting of individual clasts within a finer-grained matrix that have become cemented together. Conglomerates are sedimentary rocks consisting of rounded fragments and are thus differentiated from breccias, which consist of angular clasts...
rocks. These sedimentary rocks are from the Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
period, laid down 395 to 345 million years ago. Part of the Merimbula group placed above Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
sediments.
Nearby species include the rare Imlay Boronia
Boronia imlayensis
Boronia imlayensis, commonly known as the Mount Imlay Boronia, is a shrub of the genus Boronia which has been recorded only on the sandstone ridge near the summit of Mount Imlay, in Australia. A small shrub to 1 m high with pinnate leaves and pink to white flowers, it is found in eucalypt woodland...
, also only found on this mountain. Other nearby plants include Tea Tree
Leptospermum scoparium
Leptospermum scoparium is a shrub or small tree native to New Zealand and southeast Australia. Evidence suggests that L. scoparium originated in Australia before the onset of the Miocene aridity and dispersed relatively recently from Eastern Australia to New Zealand. It is likely that on arrival...
, Devil's Twine
Cassytha pubescens
Cassytha pubescens the Devil's Twine is a common twining plant of the Laurel family, in southern and eastern Australia. A hemi-parasitic climber....
, Digger's Speedwell, Tasmanian Flax-lily
Dianella tasmanica
Dianella tasmanica, commonly known as the Tasman Flax-lily or Tasmanian Flax-lily is a herbaceous strappy perennial herb of the family Xanthorrhoeaceae, subfamily Hemerocallidoideae, found in southeastern Australia and Tasmania. It has leaves to 80 cm, flower stem to 1.5 m, and the berries are not...
, Rasp Fern
Doodia media
Doodia media, also known as rasp fern , is a species of fern in the Blechnaceae family. The genus authority is R. Br.. Distribution of the species includes New Zealand's North Island and the upper part of the South Island...
, Spiny-head Mat-rush
Lomandra longifolia
Lomandra longifolia, commonly known as Spiny-head Mat-rush, Spiky-headed Mat-rush or Basket Grass is a perennial, rhizomatous herb found throughout eastern Australia. The leaves are 40 cm to 80 cm in long, and generally have a leaf of about 8mm to 12mm wide . It grows in a variety of soil...
, Scented Paperbark
Melaleuca squarrosa
Melaleuca squarrosa, the Scented Paperbark, is a plant native to south-eastern Australia. It is a summer-flowering shrub growing to about 5 m in height, occasionally a small tree up to 12 m, with papery bark.-Distribution:...
, Common Shaggy Pea
Oxylobium ellipticum
Oxylobium ellipticum, known as the Common Shaggy-pea is a common small plant in the pea family, found in south-eastern Australia....
, Narrow-leaved Peppermint
Eucalyptus radiata
Eucalyptus radiata is a medium to tall tree to 30 m high with persistent bark on the trunk and larger branches or persistent to smaller branches. The bark shortly fibrous , grey to grey-brown, shedding in long ribbons...
and Blotchy Mint-bush.
The Imlay Mallee has probably adapted to the relatively high levels of rainfall, mountain mist, and occasional fires
Bushfires in Australia
Bushfires in Australia are frequently occurring events during the hotter months of the year due to Australia's mostly hot, dry climate. Large areas of land are ravaged every year by bushfires, which also cause property damage and loss of life....
. It is suggested that changes to the micro habitat may be hazardous to the plant's survival.
Taxonomy
The holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of this species was collected in May 1979. The specific epithet imlayensis is named after Mount Imlay. This plant was placed in the Eucalyptus genus. Within the subgenus Symphyomyrtus, the section Maidenaria, the series Johnstonianae and the subseries Imlayensosae. This isolated species appears to be related to the eucalyptus plants of Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...
.
Dieback
The fungus Phytophthora cinnamomiPhytophthora cinnamomi
Phytophthora cinnamomi is a soil-borne water mould that produces an infection which causes a condition in plants called root rot or dieback. The plant pathogen is one of the world's most invasive species and is present in over 70 countries from around the world.- Life cycle and effects on plants :P...
is a possible cause for the deaths of individual Imlay Mallees in recent times, as is insect attack and drought. Galls on leaves have been observed, caused by an unknown psyllid. Despite the requirement of fires to promote seed germination and new growth in many eucalyptus species, it is not considered advisable to burn this area.
The population of this species consists of around 80 mature plants, with no juveniles. Natural regeneration seldom occurs, though the tree may re-sprout from the base after fire. In recent years the population has declined
Forest dieback
Forest dieback is a condition in trees or woody plants in which peripheral parts are killed, either by parasites or due to conditions like acid rain and drought....
, and the Imlay Mallee is now considered critically endangered
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
by extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
in New South Wales.