Machilus

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Lauraceae
Machilus thunbergii leaves, formerly Persea thunbergii
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Magnoliids
Order: Laurales
Family: Lauraceae
Genus: Machilus
Airy Shaw
Species

See text.

Machilus is a genus of flowering plants belonging to the family Lauraceae. Is distributed in temperate, tropical and subtropical Asia. Machilus genus include currently more than 100 species, mostly in laurel forest habitat.

Contents

[edit] Overview

The distribution of genus Machilus is temperate, subtropical, and tropical forest, occurs Continental China, Korea, Japan, Taiwan, Vietnam, Laos, Cambodia, Indonesia, Borneo, and the Philippines. The Japan are home to one of the world’s largest bay trees, Machilus thunbergii. Massive specimens are found throughout Japan, at temples and shrines, public parks, and of course in their native forests. The trunk itself can grow to over a meter in diameter. The leaves are dark green and shiny, 8-15 cm long and 3-7 cm wide. This trees are impressive broadleaf hardwoods, outdone only by the camphor tree, Cinnamomum camphora. The genus Persea was formerly treated in three subgenera. The Asian Machilus is treated in a separate genus Machilus by many authors, including in the Flora of China, while graft-incompatibility between sgenus Persea and genus Eriodaphne suggests that these too may be better treated as distinct genera, in fact Kostermans (1993) founded the genus Mutisiopersea for these. Another closely related genus, Beilschmiedia, is also sometimes included in Persea.

Many species, present multiple relict refugia from a warmer and wetter Tertiary. Machilus are lauraceae evergreen trees or shrubs from laurel forest habitat which distributed mainly in the warm tropical and subtropical areas of Asia. Machilus thunbergii is a large, evergreen tree distributed widely in the Asian continent, southern Korea, Japan, the Bonin islands, the Ryukyus, Taiwan and the Philippines. Machilus kusanoi is endemic to Taiwan and is distributed from the lowlands to 1400 m, but occurs mainly within the Ficus–Machilus Zone (< 500 m, 23–26º C). Machilus thunbergii is distributed at about 200–2000 m and occurs mainly in the Machilus–Castanopsis zone (500–1500 m, 17–23º C) (Su, 1984). M. thunbergii and M. kusanoi, are two closely related species with different altitudinal distributions, differing in their patterns of genetic diversity and recolonization dispersal. They Was tested in Taiwan in the existence of a single refugium or multiple refugia area from pleistocene. A multiple refugia pattern, explains the phylogeographical patterns of these two closely related species. [1]

[edit] Characteristics

The evergreen trees or shrubs in genus Machilus[2][3] some species are massive broad leaved evergreen trees growing 30 m tall. They are characterized in the family Lauraceae by its leaves alternate, entire, pinnately veined. Inflorescences usually paniculate, terminal, subterminal, or arising from near base of branchlet, with long peduncles or rarely without peduncles. Flowers bisexual, small or larger. Perianth tubes short; perianth lobes 6 in 2 series, equal, subequal, or occasionally outer ones conspicuously smaller than inner ones, usually persistent, rarely deciduous. Fertile stamens 9 in 3 series, anthers 4-celled, 1st and 2nd series of stamens eglandular, anthers introrse, 3rd series of stamens glandular, anthers extrorse or lateral, glands stipitate to sessile. Staminodes in 4th series, sagittate. Ovary sessile; stigmas small, dish-shaped or capitate. Fruit fleshy, globose, rarely ellipsoid or oblong, subtended at base by persistent and reflexed perianth lobes; fruiting pedicel not enlarged or slightly enlarged.

[edit] Ecology

This genus reported for Asia, currently includes 100 species, classified into tropical and subtropical south and south east Asia; 82 species in China with 63 endemic species; one additional species (endemic) is of uncertain placement. The genus species distribution range is from Yunnan to Borneo and the Philippines. The differences are ecological adaptations to different environments over a relatively dry-wet climate. Species in less humid environment are smaller or less robust, with less abundant and thinner foliage and have oleifera cells that give trees a more fragrant aroma. Machilus chekiangensis is the most common species tree in forests near Hong Kong.

The asian genus Machilus was placed under the genus Persea, due to the close relationship that exists between them. However, the differences found between genus were strong enough to be defined Machilus as a separate genus. Due to the low density, exploitation of the natural populations is to the detriment of the rainforest.

Fruits are fleshy. The fruit, a berry, are an important food source for birds, usually this birds are from specialized genus: Columbidae, Turdidae, etc. Seeds are spread by birds. Birds eat the whole fruit and regurgitate seeds intact, expanding the seeds in the best conditions for germination (ornitochory). In some species the seed dispersal is carried out by monkeys, chipmunks, rodents, Opossums or fishes.

The ecological requirements of the genus, are mostly those of the laurel forest and like most of their counterparts laurifolia in the world, they are vigorous species with a great ability to populate the habitat that is conducive. Machilus responded to favourable climatic periods and expanded across the available habitat.

The Machilus genus has led to endemic species on islands, but not so widespread geographically as in the past.

The main centers are found inhabiting wet lands in tropical or subtropical montane forests or coastal rainforest or coastal temperate forest in low-altitude. Machilus genus have adapted to more extreme conditions but mostly depending on favorable soil edaphic conditions, as presence of aquifers, groundwater, rivers, periodic flows, etc. They does not form large stands but rather small groups of trees with a density of up to one individual per five hectares. Some species have been used for a long time to produce essential oils for the pharmaceuticals industry.

The patterns of speciation in the Machilus genus indicate that since the onset of aridification on the Earth planet, iMachilus diversified in species with the majority of species the product of vicariance. The fragmentation of once more continuous area facilitated isolation of populations and this likely caused the increase in the rate of speciation.

They grow mostly in tropical forests and cloud forest, But has also been found in stubbles, pastures, in the coastal ranges and interior in wet areas to dry regions. The islander machilus species can not enduring the bad winter, from continental climate. Those garden cultivated species outside its natural distribution could be killed by continental winter, but there are exception, Machilus thunbergii from Japan, grow in snowland area.

[edit] Species

It contains the following species[4], but this list is incomplete:

[edit] References

http://flora.huh.harvard.edu/china/PDF/PDF07/Machilus.pdf http://ntur.lib.ntu.edu.tw/bitstream/246246/161801/1/19.pdf

  1. ^ http://ntur.lib.ntu.edu.tw/bitstream/246246/161801/1/19.pdf
  2. ^ http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=119262
  3. ^ http://flora.huh.harvard.edu/china/PDF/PDF07/Machilus.pdf
  4. ^ http://www.theplantlist.org/browse/A/Lauraceae/Machilus/


Stub icon This Laurales-related article is a stub. You can help Wikipedia by expanding it.
Retrieved from "http://en.wikipedia.org/w/index.php?title=Machilus&oldid=459299019"
Personal tools
Namespaces

Variants
Actions
Navigation
Interaction
Toolbox
Print/export
Languages