Storax tree plants
| Storax tree plants | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Benzoin resin tree ( Styrax benzoin ), illustration |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Styracaceae | ||||||||||||
| DC. & Blast. |
The Storax tree plants (Styracaceae) are a plant family from the order of the heather-like (Ericales) within the flowering plants (Magnoliopsida). It consists of about eleven genera with about 150 to 180 species. Some species are used as ornamental plants in parks and gardens. Resins are supplied by individual types.
description
Vegetative characteristics
They are all resinous, woody species: trees and bushes . They are mostly deciduous, rarely evergreen. The leaves, young twigs and fruits of the Storax family are almost always covered with multicellular, complex, star or shield-shaped hairs ( trichomes ), which often give them a typical silvery or brownish sheen.
The alternate and spirally arranged leaves on the branches are divided into a petiole and a leaf blade. The undivided (simple) leaf blade has a mostly serrate, rarely simple or rarely lobed edge. The stomata are anomocytic. Stipules are usually nonexistent or very small.
Inflorescences and flowers
The flowers are usually in supposedly terminal or clearly lateral, paniculate or racemose inflorescences , rarely also in compact clusters or are sometimes individually. There are no bracts .
The radial symmetry , mostly hermaphrodite and not particularly large flowers are four or five-fold 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 petals and stamens. There are usually four to five (zero or two to nine) sepals that clearly grow together in the shape of a bell or a cup, sometimes calyx teeth are hardly visible. The mostly four to five, rarely up to eight, mostly white petals are only a little fused together at the base, only completely free in the genus Bruinsmia . Stamens are usually double, rarely up to four times as many or rarely only as many as petals; they are only fused with the petals at their base or at most up to half their length and appear to be standing in a single circle. The compact stamen goes more or less into the dust bag without a clear demarcation. Usually two to four, rarely five carpels are fused to form a half to completely subordinate ovary. In each ovary compartment there are few to only one upright or hanging, anatropic, uni- or bitegmische, tenuinucellate ovules . The style ends in a cephalic or two- to five-lobed scar.
Fruits and seeds
Fruits can usually be loculicidal capsule fruits , rarely stone fruits , or sometimes winged nut fruits . Although the ovary consists of three to five carpels , and the lower part of the fruit is divided accordingly, the fruits rarely contain more than one or two to four seeds (rarely up to 50). The brown seeds are often ellipsoidal to spherical. In 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 the flavonols kaempferol and quercetin . The basic chromosome number is n = 8.
distribution
The origin of the Styracaceae is in Eurasia . The earliest known fossils assigned to the Styracaceae family date from the early Eocene . Fossil finds attest to the earlier widespread distribution in a closed area. It only spread to North America later. Today's disjoint area extends to all relict areas (refuges) of the tertiary mixed forests in the northern hemisphere . On the European mainland, all species have become extinct except for the Styrax officinalis found in the Mediterranean area .
Today this family has two main centers of development (centers of biodiversity): On the one hand, many species occur in the tropics of South America and north to Mexico ( Neotropic ). On the other hand, around half of the species are found in East Asia and Southeast Asia. In the Chinese deciduous forest areas in particular, there is a large number of endemic species that were only described at the beginning of the 20th century (for example from the small genera Sinojackia , Melliodendron and Rehderodendron ). So the family has a disjoint area. Individual species are also found in warm-temperate to tropical areas of the New World and from Asia Minor to the Mediterranean area. No species are found in the Philippines, Australia, the central Pacific, and Africa. The African taxa previously classified here are now classified in other families. In China there are ten genera, two of which are found only there, and about 54 species, 32 of which are only found there.
Systematics
The family name Styracaceae was created in 1821 by Augustin-Pyrame de Candolle and Kurt Polycarp Joachim Sprengel in Elem. Philos. Pl. , 140 first published. The type genus is Styrax L. A synonym for Styracaceae DC. & Blast. is Halesiaceae D.Don . This family was previously included in the order of the Ebenales Engler and is now included in the Ericales.
The family consists of eleven genera with around 150 to 180 species:
- Alniphyllum Matsum. : With three species in Southeast Asia and southern China.
- Bruinsmia Boer. & Coord .: With only two species from southern to southeast Asia to Malaysia .
-
Changiostyrax C. T. Chen : With the only species:
- Changiostyrax dolichocarpa (CJ Qi) CT Chen (Syn .: Sinojackia dolichocarpa C. J. Qi ). It is endemic to bushes on mountain slopes or along rivers at altitudes between 400 and 500 meters only in Shimen Xian in the province of Hunan in eastern China.
- Snowdrop trees ( Halesia J. Ellis ex L. ): With three (earlier to five) species. It has a disjoint area with two species in the southeastern US and one species in eastern China. A species sometimes called lily of the valley tree ( Halesia carolina L. ) is planted as an ornamental plant in parks and gardens because of its beautiful hanging racemose inflorescences with white flowers.
- Huodendron Rehder : With about four species in eastern Asia.
-
Melliodendron Hand.-Mazz. : With the only kind:
- Melliodendron xylocarpum Handel-Mazzetti : This species occurs only in eastern China in Fukien, northern Guangdong, northwestern Guangxi, Guizhou, Hunan, Jiangxi, southern Sichuan and southeastern Yunnan at altitudes between 600 and 1500 meters.
- Parastyrax W.W.Sm. : With only two species in southwest China and Myanmar .
- Winged torax trees ( Pterostyrax Siebold & Zucc. ): With around four species in eastern Asia. With filigree white flowers in pendulous racemose inflorescences, because of which two of the four species are sometimes planted as ornamental trees, but have been somewhat forgotten. The fruits are leathery and the seeds are strongly winged.
- Rehderodendron Hu : With around five species in southwest China, Vietnam and Myanmar.
- Sinojackia Hu : With around four to eight species only in China. One species was placed in a new genus Changiostyrax .
- Storax trees ( Styrax L. ): Including the species of the earlier genera Anthostyrax Pierre , Foveolaria Ruiz & Pav. And Pamphilia Mart. ex A. DC. With around 120 to 150 species the most species-rich (80% of the species) genus of the family and is also represented by species in most of the total range of this family. Many species occur in South America, five species in North America, 31 species in China. Among the species of the Storax tree ( Styrax officinalis ), from which the Storax resin was obtained until the 18th century , which was used in incense or in perfumes. In addition, the benzoin tree ( Styrax benzoin ) and the Siam benzoin tree ( Styrax tonkinensis ), which also provide fragrant resins.
Sources and literature
- The Styracaceae family on the AP website. (Section systematics and description)
- The Styracaceae family at L. Watson & MJ Dallwitz: The families of flowering plants at DELTA. (Section description)
- Shumei Huang & James W. Grimes: Styracaceae in the Flora of China , Volume 15, p. 253: Online. (Section description)
- Peter W. Fritsch: Styracaceae in the Flora of North America , Volume 8, p. 339: Online. (Section description)
- 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 Schönenberger, 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.
Web links
Individual evidence
- ↑ a b Styracaceae in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
- ↑ CT Chen: Changiostyrax, a new genus of Styracaceae from China , in Guijaia , 15, 1995, pp. 289-292.
- ^ B. Wallnöfer: A revision of Styrax L. section Pamphilia (Mart. Ex A. DC.) B. Wallnöfer (Styracaceae) , in Ann. Nathist. Mus. Wien , 99, 1997, pp. 681-720.