Styracaceae

Benzoin resin tree ( Styrax benzoin )

The Storaxbaumgewächse ( Styracaceae ) are a family of plants of the order of the heather -like ( Ericales ) within the angiosperms ( Magnoliopsida ). It consists of about eleven genera with about 150-180 species. Some species are used as ornamental plants in parks and gardens. Individual species provide resins.

Description

Vegetative characteristics

There are consistently resinous, woody species: trees and shrubs. They are mostly deciduous, rarely evergreen. The leaves, young branches and fruits of Storaxbaumgewächse are almost always occupied with multicellular, complex, star - or shield-shaped hairs ( trichomes ), which often gives them a typical silvery or brownish sheen.

The alternate and spirally arranged on the branches leaves are divided into petiole and leaf blade. The undivided (simple) leaf blade has a serrated usually, rarely simple or rarely lobed margin. The stomata are anomocytisch. Stipules are usually not available or very small.

Inflorescences and flowers

The flowers are usually in supposedly terminated or significantly pendent, racemose or paniculate inflorescences, rarely also in compact clumps together or are sometimes individually. There are no bracts present.

The radial symmetry, usually hermaphrodite and not particularly large flowers are usually four or fünfzählig mostly with double perianth. The flower cup ( hypanthium ) is fused with the ovary wall at different heights and is longer than sepals but lower than the Kron and stamens. There are usually four to five (zero or two to nine ) sepals that distinctly grow together bell - to cup-shaped, sometimes calyx teeth are barely visible. The generally four to five, rarely up to eight, mostly white petals are fused together at the base only a little, just in the genus Bruinsmia completely free. Stamens are twice rarely present up to four times as many or rarely the same number as petals in the rule; they are fused with the petals only at its base or to a maximum of half their length and act as standing in a single circle. The squat thread is more or less dust into the dust bag via without clear demarcation. Usually two to four, rarely five carpels are semi - to completely inferior ovary fused into one. In each ovary compartment are only a few to an upright or inverted, anatrope, uni- or bitegmische, tenuinucellate ovules. The style ends in a capitate or two-to five-lobed stigma.

Fruit and seeds

Fruits can be mostly lokulizidale capsule fruits, rare stone fruits, or even, sometimes winged nut fruits. Although the ovary of three to five carpels is, and the fruit is separated according to the lower part of the fruits rarely more than one or two, or four seeds contain ( often up to 50). The brown seeds are often ellipsoid to globose. For some (example: Alniphyllum ) genera the seeds are flat and winged or strongly ribbed. The abundant endosperm is oily. The embryo is straight or slightly curved.

Ingredients and chromosome numbers

They contain saponins and flavonols kaempferol and quercetin. The basic chromosome number is n = 8

Dissemination

The origin of the Styracaceae located in Eurasia. The earliest known fossils that are associated with the family of Styracaceae, date from the early Eocene. Fossil finds testify to the former prevalence in a closed area. The spread to North America took place only later. Today disjoint area extends to all areas of relict ( refugia ) of the Tertiary mixed forests in the northern hemisphere. In continental Europe, all species have become extinct except for the occurring in the Mediterranean area Styrax officinalis.

This family now has two main deployment centers ( centers of biodiversity ): First, many species occur in the tropics of South America and north to Mexico before ( Neotropics ). Secondly, there is about half of the species in East Asia and Southeast Asia. In particular, we find in the Chinese deciduous forest areas, a larger number of endemic species that have been described only in the early 20th century ( for example, from the small genera Sinojackia, Melliodendron and Rehderodendron ). The family also has a disjoint area. Some species are also found in warm temperate to tropical regions of the New World, from Asia Minor to the Mediterranean. No species are in the Philippines, Australia, in the central Pacific and Africa. The formerly classified here African taxa are now classified in other families. In China, you will find ten, only two of them there, genera and about 54 species, of which 32 occur only there.

System

The family name was Styracaceae 1821 by Augustin- de Candolle and Kurt Pyrame Polycarp Joachim Sprengel in Elem. Philos. Pl, 140 first published. Type genus is Styrax L.. A synonym for Styracaceae DC. & Spreng. is Halesiaceae D.Don. This family was previously attributed to the order of the Ebenales Engler and is now classified in the Ericales.

The family consists of eleven genera with about 150 to 180 species:

• Alniphyllum Matsum. With three species in Southeast Asia and southern China.
• Bruinsmia Boer. & Coord: With only two species from the southern to southeastern Asia to Malaysia.
• Changiostyrax C. T. Chen, with only one type: Changiostyrax dolichocarpa (CJ Qi ), Chen CT ( Syn: Sinojackia dolichocarpa CJ Qi ). It is endemic in thickets on mountain slopes or along rivers at altitudes between 400 and 500 meters only in Shimen Xian in Hunan Province in eastern China.

• Melliodendron xylocarpum Handel-Mazzetti: This species is found only in the eastern China in Fukien, northern Guangdong, northwestern Guangxi, Guizhou, Hunan, Jiangxi, southern Sichuan and southeastern Yunnan at altitudes 600-1500 meters in front.

Sources and Literature

• The Styracaceae on the APWebsite family. ( Section systematics and description)
• The Styracaceae family in L. Watson and MJ Dallwitz: The families of flowering plants at DELTA. ( Description section )
• Shumei Huang & James W. Grimes: Styracaceae in the Flora of China, Volume 15, p 253: Online. ( Description section )
• Peter W. Fritsch: Styracaceae in the Flora of North America, Volume 8, page 339: Online. ( Description section )
• Peter W. Fritsch, Cynthia M. Morton, Tao Chen & Candice Meldrum: Phylogeny and Biogeography of the Styracaceae, in International Journal of Plant Sciences, Volume 162, Supplement 6, 2001, pp. 95-116.
• Jürgen Schönberger, Arne A. Anderberg & Kenneth J. Sytsma: Molecular Phylogenetics and Patterns of Floral evolution in the Ericales, in International Journal of Plant Sciences, 166, 2, 2005, pp. 265-288. .