''Zanthoxylum brachyacanthum'', known as thorny yellow-wood, satinwood, satin tree or scrub mulga, is a species of flowering plant in the family

Rutaceae The Rutaceae is a family, commonly known as the rueRUTACEAE
in BoDD – Botanical Der ...

and is

endemic Endemism is the state of a species being found 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 found else ...

to north-eastern Australia. It is a rainforest shrub or tree with thick, cone-shaped spines on the trunk and prickles on the branches,

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

leaves, and male and female flowers arranged in panicles.

Description

''Zanthoxylum brachyacanthum'' is a shrub or tree that typically grows to a height of usually with prickles on the branches and thick, cone-shaped spines on the trunk and older branches. The leaves are pinnate, arranged alternately, with seven to thirteen leaflets, and long. The leaflets are egg-shaped to elliptic, long and wide, the side leaflets on a petiolule long and the end leaflet on a petiolule long. The flowers are arranged in panicles on the ends of branches, or in leaf axils or both and long. The flowers 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 ...

or on

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

up to long, the four

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s joined at the base and about long, the four petals greenish cream-coloured and long. Male flower have four stamens long with anthers about long. Females flowers have a single

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...

about long with a short

style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...

, sometimes with rudimentary stamens. Flowering occurs from September to November and the fruit is a shiny bright red, later wrinkled dark brown, spherical or oval follicle long containing a single black seed.

Taxonomy

''Zanthoxylum brachyacanthum'' was first formally described in 1857 by Ferdinand von Mueller in ''Transactions of the Philosophical Institute of Victoria'' from specimens collected in "the Araucaria forests of

Moreton Bay Moreton Bay is a bay located on the eastern coast of Australia from central Brisbane, Queensland. It is one of Queensland's most important coastal resources. The waters of Moreton Bay are a popular destination for recreational anglers and are ...

". ''Zanthoxylum veneficum'', listed as a synonym of ''Z. brachyacanthum'' 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 Syst ...

, is recognised as a different species in Queensland.

Distribution and habitat

This tree grows on a variety of subtropical, tropical and drier rainforests, often on volcanic soils. Young trees are easily identified in the rainforest by the thorny trunk. The natural range is from the Clarence River (29° S) in

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

to tropical

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

in the

Eungella National Park Eungella National Park ( ; meaning "Land of the clouds") is a protected area in Queensland, Australia. It is on the Clarke Range at the end of the Pioneer Valley 80 km west of Mackay, and 858 km northwest of Brisbane. Eungel ...

and the Wet Tropics region.

Ecology

The leaves of ''Zanthoxylum brachyacanthum'' serve as a food plant for

butterfly Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprise ...

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e including those of the orchard swallowtail butterfly, the fuscus swallowtail and '' Papilio polyctor''.

Uses

This tree's small size, the interesting trunk, the attractive flowers and foliage makes the thorny yellowwood a candidate ornamental plant. The timber is deep yellow and close grained, and thus it might be suitable for decorative work. The plant family contains some interesting

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

coumarins Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...

furanocoumarins The furanocoumarins, or furocoumarins, are a class of organic chemical compounds produced by a variety of plants. Most of the plant species found to contain furanocoumarins belong to a handful of plant families. The families Apiaceae and Rutacea ...

, and pyranocoumarins,

acetophenones Acetophenone is the organic compound with the formula C6H5C(O)CH3. It is the simplest aromatic ketone. This colorless, viscous liquid is a precursor to useful resins and fragrances. Production Acetophenone is formed as a byproduct of the cumene p ...

such as Zantholoxylin,

flavanoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s like amurensin, and polyhydroxol flavanoids, and Amides. The essential (leaf) oil of Z. brachyacanthum was rich in

α-pinene α-Pinene is an organic compound of the terpene class, one of two isomers of pinene. It is an alkene and it contains a reactive four-membered ring. It is found in the oils of many species of many coniferous trees, notably the pine. It is also ...

(46%), β-caryophyllene (14%) and bicyclogermacrene (12.5%). Image:Zanthoxylum brachyacanthum female.jpg, Female flowers Image:Zanthoxylum brachyacanthum male.jpg, Male flowers Image:Zanthoxylum brachyacanthum fruit.jpg, Fruit

References

* Floyd, A.G., ''Rainforest Trees of Mainland South-eastern Australia'', Inkata Press 1989, {{Taxonbar, from=Q3024456 brachyacanthum Flora of New South Wales Flora of Queensland Sapindales of Australia Trees of Australia Taxa named by Ferdinand von Mueller Plants described in 1857