Lauraceae

Azores laurel (Laurus azorica )

The laurel family ( Lauraceae ) are a family of angiosperms ( Magnoliopsida ). It includes about 50 genera with 2000-2500 species that are widespread in tropical areas. Almost all representatives are perennial trees or shrubs, with the Cassytha but there is also a genus of parasitic vines within the family. Of particular importance for the people who cinnamon and bay leaves, which are used as a spice due to the aromatic ingredients.

• 4.1 Outer systematics
• 4.2 Internal systematics

• 5.1 Notes and references

Description

Appearance, bark, wood and roots

Laurel plants are usually evergreen, rarely deciduous trees or shrubs, the only exception is the genus Cassytha whose types hemiparasitische, twining perennial herbaceous plants. The smallest Shrubby growing species rarely reach heights of growth of 1 meter, under the trees, species with growth heights of up to 50 meters. Some species grow easily climbing, are, therefore, compelled to be supported by neighboring plants. In many species, all plant parts smell aromatic.

The trees usually have a smooth bark that is often filled with a variety of round, flat Korkporen, but it is also heavily cracked bark occur.

The wood can be very easy to extremely strong, the relative density is usually between 0.4 and 0.8 g/cm3, but can reach 0.2 g/cm3 to 1.3 g/cm3.

Within the family buttress roots are commonly found, but pronounced buttress roots remain the exception. Rarely, breathing roots and stilt roots are found.

The usually alternate, rarely opposite or seemingly arranged in whorls leaves are usually divided into petiole and leaf blade. The leaf blades are usually simple, entire and often leathery. The upper leaf surface is usually dark green and glossy, the lower leaf surface is often blue-green. Size and shape are highly variable within the family, the smallest are only about 1 cm long, the longest reach more than 60 cm in length; the shape ranges from circular to band form. Notwithstanding the scale-like leaves in the genus Cassytha and lobed leaves that occur in the genus Sassafras, in young foliage leaves in the genus Actinodaphne and two species of the genus Lindera. The coat consists exclusively of unicellular trichomes that may appear chambered something. They vary in size, shape, orientation and density, but can also almost completely absent. In most cases the hair on the top is denser than on the bottom. The venation is usually fiederig, in many genres, however, also occur leaves with three main veins. On the bottom are occasionally found Domatien in the axils of the veins. Stipules are not formed within the family.

Inflorescences and flowers

The pendent inflorescences are usually closed and thyrsenförmige panicles up Botryoiden or pseudo- umbels. They are rarely combined to form heads, or reduced to a single flower. Some representatives form inflorescences with several hundred flowers. The inflorescences within the genus Cassytha and some species of Litsea and Mezilaurus are open, in the way Licaria capitata the internodes of the inflorescence are greatly reduced, so that a capitate inflorescence is produced, which is on a long peduncle. Rarely, the entire inflorescence is surrounded by large bracts, often several umbel- shaped groups of flowers that are surrounded by high leaf sheaths or inflorescences, in which high - or bracts absent.

The flowers may be bisexual or unisexual. If the flowers are unisexual may be the species dioecious, or monoecious polygamomonözisch. Unisexual flowers occur among others in the genera Actinodaphne, Endlicheria Lindera, Neolitsea and Rhodostemonodaphne.

The flowers are relatively small with diameters of usually from 2 to 8 mm, 1-20 mm radial symmetry. The detached from the carpel base of the flower may be more or less high cup-shaped, small or significantly enlarged and urn -shaped pronounced.

The flowers are usually in threes. Twofold flowers come in the species of laurels (Laurus ), in Neolitsea and Potameia, in the genus Endiandra at Endiandra xanthocarpa and occasionally in Cinnadenia before; fourfold or irregular flowers there are in the genus Chlorocardium.

The perianth consists in most cases of two circles usually equal multiform or sometimes as differently shaped bloom. Occasionally, the bloom of the outer circle to ½ to ¼ smaller than that of the inner circle. By way of derogation, the genera Dicypellium and Phyllostemonodaphne to three and Eusideroxylon four circles of bloom cladding, which represent the inner circles converted Stamen circles. The genera Litsea and Lindera parts of the perianth can be converted into stamens, so that bloom can also completely missing. The colors of the bracts range from usually greenish, yellowish, whitish to white or rarely reddish. The bloom are erect, spreading or reflexed; Often they are bent inwardly.

The stamens are initially in four circles of three each, of which the innermost circle is usually sterile or may be missing. Occasionally, one or two of the remaining three groups are sterile stamen or absent. In some genera the number of stamens is higher, at Actinodaphne ( up to 15), Chlorocardium ( up to 20), Cinnadenia ( up to 32), Dodecadenia ( up to 18 ), with the laurels (Laurus ) (up to 30 ), of the genus Lindera (up to 15) and Litsea ( up to 20). There is often a pair of glands at the base of the stamens of the inner circle present. The anthers are two - or vierkammerig and open over flaps usually from the base to the tip. Usually, the dust bag of the outer two circuits are turned inwards, the third circuit can be turned to the outside. In some species of the genus Potameia and rarely in the genera Endiandra and Beilschmiedia the dust bag by fusion of the pollen sacs are single chamber. The pollen grains are more or less spherical in shape and usually have a diameter of 18 to 40 microns, rare 14-70 microns. The pollen grain surface is covered mostly with 0.5 to 2 (rarely to 3) microns high spikes.

There is only one carpel available, which is usually above the time, exceptions are the genera Hypodaphnis in it where it is inferior and Eusideroxylon and Potoxylon semi - inferior. The only carpel contains a single, anatrophe ovule. The scar is three-lobed, disk-or kidney-shaped.

Fruit and seeds

As fruits berries are usually formed that contain a single large seed. Rarely there are also stone fruit, with weak endocarp. The fruit shape varies pressed between spherical to club-shaped or almost fusiform, but usually they are elliptoid. The fruits are mostly fleshy or rarely woody. The smallest fruits are only about 5 mm long, the biggest there is in the cultivated avocado ( Persea americana) with over 15 cm in length. The base of the flower and the flower stem on the fruit can either be increased or hardly but increased significantly. Then they often form a fleshy or woody fruit cups around the lower part of the fruit, reminiscent of acorns. The surface of the fruit ( exocarp ) is usually shiny black or dark purple to brownish, sometimes it is covered with a bluish waxy layer; other fruit colors such as red, light brown, green, yellow or white are rare.

The seed coat ( testa) is thin, an endosperm does not exist. The embryo is completely formed, straight and very has large cotyledons.

Use and importance

Today economically important species is the avocado ( Persea americana). Their fruit is used mainly as salad fruit. The oil obtained from the fruit and the seed is mainly used in the cosmetics industry.

Many members of the laurel family are used as a spice due to its aromatic fragrance. Especially cinnamon, which is obtained from the bark of young branches of the Ceylon cinnamon tree ( Cinnamomum verum), it has a special meaning. Often, the bark is used closely related species, but these are often of inferior quality. The Cassia ( Cinnamomum cassia ), for example, provides a less intense smelling bark.

The use of the leaves of the laurel Real is known from the Mediterranean region since ancient times. Already recipes from the cookbook of Apicius Marcus Gavius ​​demonstrate the use. In the traditions of Greek mythology Daphne turned into a laurel tree to hide from her Vereherer Apollo, who was in turn from mourning wreaths of laurel leaves. Laurel leaves were also used in Greece to honor Olympians, in the Roman Empire were honored victorious generals with laurel wreaths.

More used as spices, plants are the sassafras tree ( Sassafras albidum ) and Litsea glaucens, Cinnamomum tamala. Some species that have never been cultivated, are threatened due to extensive use as a spice in their inventory, such as Dicypellium caryophyllaceum.

For the perfumery aromatic oils are extracted from some species, such as rosewood oil from Aniba rosaeodora or the Brazilian sassafras from Ocotea odifera. Dating back to the camphor ( Cinnamomum camphora ) won camphor is used in the pharmaceutical industry, and there is a variety of uses of different types of folk medicine.

Supply many kinds of wood, which is at least in the local context of use, on the world market have only a few representatives of the family importance as a timber, such as Chlorocardium rodiaei, Eusideroxylon zwageri, Ocotea porosa and Endiandra palmerstonii.

Occurrence

The Lauraceae family has a pantropical distribution, some species range in the north and the south to temperate regions. Has the northernmost distribution in the Old World genus Lindera, which extends to the Japanese island of Hokkaidō, the southern Old World representatives are three species of the genus Beilschmiedia to New Zealand. In the New World Sassafras albidum reaches up to Maine and in southern Ontario in the south Persea lingue limited to the Chilean island of Chiloe, the area of ​​distribution. The centers of distribution of the family are in the Indo- Malay areas and in Central America to South America. In Tropical Africa, however, only relatively few species are represented. In the Neotropics, there are 27 genera.

Species of the Lauraceae family come in tropical mountain forests ago at altitudes up to about 4000 meters, where they are often the most abundant family. In rain forests of lower altitudes, however, the absolute number of species is highest. Although in dry areas decreases the spread of the family, some species have adapted to semi-arid locations. Other species grow in other extreme locations such as temporarily flooded forest or virtually nutrient -free soil of white sand.

System

Outer systematics

The Lauraceae family is placed in the order of the laurel -like ( Laurales ) and there is the family with the highest number of species. Molecular biological studies have shown that the family along with the Hernandiaceae and Monimiaceae form a monophyletic clade, the phylogenetic relationships of the three families to each other is not yet certain exactly.

Inside systematics

This family was erected in 1789 by Antoine Laurent de Jussieu under the name " Lauri " Genera Plantarum in, p 80. Synonyms for Lauraceae Juss. are: Cassythaceae Bartl. ex Lindl. and Perseaceae Horan. ; these were separate families, each with only one genus Cassytha or Persea.

There are about 45-57 species in the laurel family ( Lauraceae ) and with about 2000 to 2500 species ( species numbers and distribution areas of the species come from Rohwer 1990 and need to be updated, except the genera that are extra marked and example of the flora were of China 2008 or Quinet updated in 2005 ):

• Actinodaphne Nees: The about 100 species are distributed in tropical and subtropical areas of Asia.
• Adenodaphne S.Moore: The maximum of five species are found only in New Caledonia.
• Aiouea Aubl. The approximately 19 species are widespread in the Neotropics.
• Alseodaphne Nees: The about 50 or more species have spread to the Philippines, Sri Lanka, India, Laos, Myanmar, Thailand, Cambodia, China, Vietnam, Malaysia, Indonesia.
• Anaueria Kosterm. (sometimes in Beilschmiedia ): it contains only one type: Anaueria brasiliensis Kosterm. It is distributed in South America.

• Apollonias arnottii Nees: It occurs in India.
• Barbusano ( Apollonias barbujana ( Cav. ) Bornm. ): It occurs in Macaronesia (Canary Islands).

• Dodecadenia grandiflora Nees: Its distribution area is India, Bhutan, Nepal, Myanmar and China.

• Eusideroxylon zwageri Teijsm. & Binn. It comes from Sumatra to Borneo before.

• Gamanthera herrerae van der Werff: It occurs only in Costa Rica.

• Hexapora curtisii Hook. f: It occurs only on the Malay Peninsula.

• Hypodaphnis zenkeri ( Engl ) Stapf: It is widespread in tropical West Africa.

• Mocinnodaphne cinnamomoidea Lorea - Hern: . It is distributed in Mexico.

• Smelly laurel ( Ocotea foetens ( Aiton ) Baill. )

• Paraia bracteata Rohwer et al.: It is distributed in Brazil.

• Parasassafras confertiflorum ( Meisner ) DGLong: It is distributed from India to Bhutan and Myanmar to the southwest and western Yunnan.

• Avocado ( Persea americana Mill )

• Phyllostemonodaphne geminiflora ( Mez ) Kosterm. It occurs in the Brazilian states of Minas Gerais and Rio de Janeiro in the Mata Atlântica.

• Potoxylon melagangai ( Symington ) Kosterm. It occurs only in Borneo.

• Povedadaphne quadriporata WCBurger: It occurs only in Costa Rica.

• Sinopora hongkongensis ( NHXia et al. ) J.Li et al.: This endemic species is very rare and grows in evergreen laurel forests at altitudes of 400 to 500 meters only in Tai Mo Shan in Hong Kong.

• Sinosassafras flavinervium ( CKAllen ) HWLi: It occurs only in the Chinese provinces südöstlichens Xizang and western Yunnan.

• California laurel ( Umbellularia californica ( Hook. & Arn ) Nutt.. ): It is distributed with two varieties in western North America.

Swell

• The Lauraceae family in APWebsite. ( Section systematics and description)
• The families Lauraceae and Cassythaceae at DELTA. ( Description section )
• Shugang Li, Xi -wen Li, Jie Li, Puhua Huang, Fa - Nan Wei, Cui Hongbin & Henk van der Werff: Lauraceae, pp. 102 - text the same online as printed work, In: Wu Zheng -yi, Peter H. Raven & Deyuan Hong (ed.):. Flora of China, Volume 7 - Menispermaceae through Capparaceae, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 2008 ISBN 978-1-930723-81-8 ( section description)
• Henk van der Werff: Lauraceae - text the same online as printed work, Flora of North America Editorial Committee ( eds.): Flora of North America North of Mexico, Volume 3 - Magnoliidae and Hamamelidae, Oxford University Press, New York and Oxford, 1997. ISBN 0-19-511246-6 ( Description section )
• JG Rohwer. Lauraceae, pp. 366-391, in: Klaus Kubitzki et al. ( Eds): The Families and genera of vascular plants, Volume 2: Flowering Plants - Dicotyledons - Magnoliid, Hamamelid and Caryophyllid Families, Springer Verlag, 1990, ISBN 978-3-540-55509-4. Google -Books -Online.
• Andre S. Chanderbali, Henk van der Werff & Susanne S. Renner: Phylogeny and Historical Biogeography of Lauraceae: Evidence from the chloroplast and nuclear genome, In: Annals of the Missouri Botanical Garden, Volume 88, Issue 1, 2001, p 104 -134.
• A. S. Chanderbali, 2009: Neotropical Lauraceae. at Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.