Gyrocarpus americanus
Encyclopedia
Gyrocarpus americanus is a flowering plant
in the Hernandiaceae
family with a wide pantropical distribution. It is commonly and variously known as the Helicopter Tree, Propeller Tree, Whirly Whirly Tree, Stinkwood or Shitwood. In Cronquist system
, this plant is considered in a separated family (Gyrocarpaceae).
, growing to about 12 m in height. The leaves
are spirally arranged, crowded near the ends of the branches, up to 150 × 120 mm in size. They are ovate, often 3-lobed, dark green above, paler and greyer below, with velvety surfaces, 3-veined from the base. The veins are yellowish and the stalk up to 90 mm long. The cream to yellowish-green flowers grow in compact heads and have an unpleasant smell. The fruit is a woody nut with two long thin wings that help wind dispersal. The winged fruit and the smell of the flowers have given the tree its various common names.
Several other subspecies have been described. Kubitzki distinguished eight – three in Madagascar, one each in tropical West and East Africa, one in tropical Australia, and one in Malesia, with the eighth being the typical subspecies G. a. americanus originating in the Palaeotropics and reaching the Neotropics by trans-Pacific dispersal. Most of these are rarely collected or are not recognised. Moreover, the monophyly
of G. americanus remains unclear; the African species G. angustifolius and G. hababensis may lie within it.
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the Hernandiaceae
Hernandiaceae
Hernandiaceae is the botanical name for a family of flowering plants. Such a family has been recognised by most taxonomists.The APG II system, of 2003 , also recognizes this family, and assigns it to the order Laurales in the clade magnoliids...
family with a wide pantropical distribution. It is commonly and variously known as the Helicopter Tree, Propeller Tree, Whirly Whirly Tree, Stinkwood or Shitwood. In Cronquist system
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...
, this plant is considered in a separated family (Gyrocarpaceae).
Description
Gyrocarpus americanus is a slender, deciduous tree with smooth, grey barkBark
Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner...
, growing to about 12 m in height. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are spirally arranged, crowded near the ends of the branches, up to 150 × 120 mm in size. They are ovate, often 3-lobed, dark green above, paler and greyer below, with velvety surfaces, 3-veined from the base. The veins are yellowish and the stalk up to 90 mm long. The cream to yellowish-green flowers grow in compact heads and have an unpleasant smell. The fruit is a woody nut with two long thin wings that help wind dispersal. The winged fruit and the smell of the flowers have given the tree its various common names.
Subspecies
- G. a. africanus Kubitzki (AfricaAfricaAfrica is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
) - G. a. americanus Jacq. (East AfricaEast AfricaEast Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the UN scheme of geographic regions, 19 territories constitute Eastern Africa:...
, IndiaIndiaIndia , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, MalesiaMalesiaMalesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
, northern AustraliaAustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, MelanesiaMelanesiaMelanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...
, PolynesiaPolynesiaPolynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
, and SouthSouth AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and Central AmericaCentral AmericaCentral America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
) - G. a. glaber Kubitzki (MadagascarMadagascarThe Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
)
Several other subspecies have been described. Kubitzki distinguished eight – three in Madagascar, one each in tropical West and East Africa, one in tropical Australia, and one in Malesia, with the eighth being the typical subspecies G. a. americanus originating in the Palaeotropics and reaching the Neotropics by trans-Pacific dispersal. Most of these are rarely collected or are not recognised. Moreover, the monophyly
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
of G. americanus remains unclear; the African species G. angustifolius and G. hababensis may lie within it.