Xanthorrhoea australis | |
---|---|
The tree flowers after a fire in The Grampians, Victoria, Australia | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Asphodelaceae |
Subfamily: | Xanthorrhoeoideae |
Genus: | Xanthorrhoea |
Species: | X. australis |
Binomial name | |
Xanthorrhoea australis | |
Xanthorrhoea australis, the grass tree or austral grasstree, [1] is an Australian plant. It is the most commonly seen species of the genus Xanthorrhoea . Its trunk can grow up to several metres tall and is often branched. In certain Aboriginal languages, it is called bukkup, baggup or kawee. [1]
The main way to identify Xanthorrhoea is by looking at the cross-section of the leaves. In the case of X. australis the cross-section is a rough diamond shape, and the colour of the leaves is a bluish-green.
The species usually develops a rough trunk which may be branched and coloured black, the result of bushfires. [2] The trunk is able to grow up to over 3 metres (9.8 ft) in height with a width of up to 1 metre (3.3 ft) and may be branched. The bark is thick, rough and corky. [3] The plant is very slow growing and trunks only start appearing after many years. The long, narrow leaves are crowded together at the tops of the trunks. [2]
X. australis takes several years to flower, and it does not always flower annually, but in the season after a bushfire it flowers prolifically. The flowers appear on a spear-like spike which can grow up to 2 metres (6.6 ft) tall. The flowers, with 6 petals, usually cover 1⁄2–5⁄6 of the stem.
The crown of leaves is almost spherical in shape, the point of each leaf perfectly marking the shape of the imagined sphere. The leaves crown the trunk in a crowded whorl of long, wiry leaves. They are arranged in a spiral, forming an erect tuft when young and spreading as they mature, with the oldest leaves dying and forming a hanging skirt around the trunk. The blue-green needle-like leaves are typically 14 to 30 centimetres (5.5 to 11.8 in) long and have a waxy coating. [3] The leaves are softer and generally less rigid than other Xanthorrhoeas. Old leaves hang down forming a distinctive skirt-like feature that partly covers the fire-blackened trunk. X. australis flowers from July to December, but younger plants may flower in June.
The common name grass tree is accurate as the trunks and branches of the tree varieties are literally made out of the leaf bases, not wood. [4]
Grass trees are often very long-lived with some estimated to be 350 to 450 years old. [5]
The species was first formally described by the botanist Robert Brown in 1810 as part of the work Prodromus Florae Novae Hollandiae. [6]
The genus name Xanthorrhoea is taken from the Greek words xanthos, meaning yellow, and rheo, meaning to flow, a reference to the resin that is obtained from these plants. The species epithet australis, meaning southern, refers to the distribution of the species. [2]
This species can be found in the states of New South Wales, Australian Capital Territory, South Australia, Western Australia, Tasmania and Victoria. It is regarded as the most widely distributed all of the Xanthorroea species. [2] It is able to survive in poor soils, is intolerant to phosphorus and is highly susceptible to the soil-borne disease Phytophthora cinnamomi . [3]
Indigenous Australians soaked the flowering spikes in water to produce a sweet drink. The soft, white leaf bases were eaten as well as the growing point of the stem. The flower spike exudes a resin which could be used as an adhesive in the manufacture of tools and the stem used for the lower portion of a spear. Stems were also used to make a base for a fire-drill to start a fire. The resin was also collected and sent to commercial processors where it was made into lacquer for furniture of cabinet makers. [1]
In 1915 there was considerable consternation over the realisation that German agents had been buying “immense quantities of grass tree gum for the past quarter of a century”, presumably for the purpose of manufacturing explosives. The explosive containing grass tree resin was reported as more explosive than dynamite in experiments at the time. [4]
Cordyline australis, commonly known as the cabbage tree, or by its Māori name of tī or tī kōuka, is a widely branched monocot tree endemic to New Zealand.
Xanthorrhoea is a genus of about 30 species of flowering plants, in the family Asphodelaceae. They are endemic to Australia.
Kingia is a genus consisting of a single species, Kingia australis, and belongs to the plant family Dasypogonaceae. The Aboriginal name bullanock is used as a common name for the plant. It has a thick pseudo-trunk consisting of accumulated leaf-bases, with a cluster of long, slender leaves on top. The trunk is usually unbranched, but can branch if the growing tip is damaged. Flowers occur in egg-shaped clusters on the ends of up to 100 long curved stems. Kingia grows extremely slowly, the trunk increasing in height by about 1½ centimetres per year. It can live for centuries, however, so can attain a substantial height; 400-year-old plants with a height of six metres are not unusual.
Xanthorrhoea preissii, known as balga, is a widespread species of perennial monocot in Southwest Australia.
Xanthorrhoea quadrangulata or the Mount Lofty Grass Tree is a plant in the genus Xanthorrhoea. It is the only species of Xanthorrhoea solely endemic to the state of South Australia.
Cordyline pumilio, commonly known as the dwarf cabbage tree, pygmy cabbage tree or by its Māori names tī koraha or tī rauriki, is a narrow-leaved monocot shrub endemic to New Zealand. It usually grows up to 1 metre tall, although rare examples of 2 metres tall have been reported. It has long leaves and can easily be mistaken for a grass or a sedge. C. pumilio grows in the north of the North Island from North Cape at 34°S to Kawhia and Opotiki at about 38°S, generally under light forest and scrub. It was cultivated by Māori as a source of carbohydrate and used as a relish to sweeten less palatable foods.
Xanthorrhoea minor is a species of grasstree of the genus Xanthorrhoea native to south-eastern Australia. It was one of the many species authored by the Scottish botanist Robert Brown.
Xanthorrhoea macronema is a forest plant in the genus Xanthorrhoea, found in coastal regions of eastern Australia north of Sydney, New South Wales to Fraser Island, Queensland. The trunk of this grass tree is underground.
Xanthorrhoea glauca, known as the grass tree, is a large plant in the genus Xanthorrhoea, widespread in eastern Australia. The trunk can grow in excess of 5 metres tall, and may have many branches. It is occasionally seen in large communities in nutrient rich soils. The leaves are a grey or bluish glaucous green.
Xanthorrhoea malacophylla is a species of grasstree of the genus Xanthorrhoea. It is endemic to New South Wales, Australia. Mature plants form a single or branched trunk that ranges between 2 and 6 metres in height. The grass-like leaves, which are usually around 3 mm wide, are distinguished from other species by their softness and sponginess. The flowers appear between May and September in scapes that are between 1.3 and 1.8 metres long.
Xanthorrhoea semiplana is a species of grass tree found in south-eastern Australia, with two subspecies:
Xanthorrhoea drummondii, commonly known as blackboy, grasstree or Drummond's balga, is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea brevistyla is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea brunonis is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea gracilis, commonly known as the graceful grasstree, grassboy or mimidi, is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea nana, commonly known as dwarf grasstree, is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea platyphylla is a species of grasstree of the genus Xanthorrhoea native to Western Australia.
Xanthorrhoea thorntonii, commonly known as Cundeelee grasstree, Cundeelee blackboy, desert grasstree, yacka or grasstree, is a species of grasstree of the genus Xanthorrhoea native to central Australia. It is known to the Pitjantjatjara people as kata-kultu, kata-puru, ulpa or urara, the Warlpiri people as yurlurnkuru and the Arrernte as lunkere. X. thorntonii is the only grass tree found in Central Australia including the Great Sandy Desert, Great Victoria Desert and MacDonnell Ranges.
Xanthorrhoea pumilio is a species of grasstree of the genus Xanthorrhoea native to Queensland.
Xanthorrhoea bracteata, the shiny grasstree, is a species of grasstree of the genus Xanthorrhoea endemic to Tasmania, Australia. It is one of many species described by Scottish botanist Robert Brown.