Elaeagnaceae

Sea Buckthorn ( Hippophae rhamnoides )

The oil of the willow family ( Elaeagnaceae ) family belongs to the order of the rose -like ( Rosales ) within the angiosperms ( Magnoliopsida ). This small family contains only three genera with about 50 to 100 species. It is distributed in the northern hemisphere and to the eastern Australia.

There are usually thorny and drought-resistant shrubs. The most important representative in Central Europe of sea buckthorn ( Hippophae rhamnoides ). Many species are used by humans.

• 4.1 Notes and references

Description

In most species occur at the roots of root nodules with symbiotic nitrogen-fixing bacteria of the genus Frankia within the Actinomycetales ( Aktinorrhiza ) ago.

Habitus and sheets

They are evergreen or deciduous, small trees or shrubs; some species are " rods plants". Some species are armed with thorns. Often there are xerophytes.

The leaves are usually alternate and spirally arranged rarely opposite or whorled seemingly on the branches. There are almost always petioles present; They may be short. The simple leaf blade is pinnately and often leathery, with more or less smooth margin. At least on the underside of the leaf blade are silvery to brown, shield -shaped cover and / or star hair, characterized the leaves often appear silvery. Stipules absent.

Inflorescences and flowers

The flowers are borne singly or in bundles, often short or racemose inflorescences aged men. The flowers are hermaphrodite or unisexual. If the flowers are unisexual then the species are mostly dioecious getrenntgeschlechtig ( dioecious ).

The radial symmetry flowers are often cruciform and often fragrant. A relatively long hypanthium is present. The usually four (two to eight ) sepals are fused, with the calyx teeth are much longer than the calyx tube; their colors range from white to cream to yellow. Petals absent. There are usually four or eight, rarely two or twelve fertile stamens present. The very short stamens are fused with each other freely, but with the sepals. In female flowers are not included in the staminodes and rudimentary male no stamp. It's just a constant upper carpel with a single ovule anatropen available. The carpel is closely enveloped by the basal area of ​​the calyx tube and acts as if it were inferior. The long style ends in a lateral scar. Pollination is by insects ( entomophily ) and wind ( anemophily ).

Fruit and seeds

The flower one achene is formed, which is enveloped by the fleshy liberated during fruit ripening base of calyx tube and as berries or drupes act and contain a single seed. The ripe fruits are often intensely colored eaten by birds and the seeds excreted undigested. Some species are known to fruit dry over the winter and be swept away in rivers.

Ingredients and sets of chromosomes

It can be stored calcium oxalate crystals. In the fruit tannins and vitamin C usually are included. Most occur alkaloids. If proanthocyanidins are present then there are cyanidin and delphinidin. Ellagic acid was detected in all three species. Most occur saponins.

The chromosome numbers amount to n = 6, 10, 11, 13

Systematics and distribution

The family name Elaeagnaceae was published in 1789 under the name of Antoine Laurent de Jussieu Elaeagni in genera plantarum, pp. 74-75. The type genus is Elaeagnus L., whose botanical name is composed of the Greek words for olive ( Olea europaea) and chaste tree ( Vitex agnus castus ). There are not valid spellings Eleagnus and Eleagnaceae.

The Elaeagnaceae family has already been asked in the orders Rhamnales, Proteales and Thymelaeales. Today, within the order of Rosales form the Elaeagnaceae with the Dirachmaceae and Rhamnaceae a clade.

Fossil pollen belonging to the family of Elaeagnaceae is known only from the Oligocene 22 to 39 million years ago. It seems that the family on the northern continent Laurasia was before it broke apart.

The total distribution area of ​​Elaeagnaceae family range from the temperate latitudes of the northern hemisphere above the tropics to eastern Australia. Two genera with 74 species occur in China, of which 59 are only there.

There are three genera in the family Elaeagnaceae with about 50 to 100 species:

• Buckthorn ( Hippophae L., Syn: rhamnoides Miller): The approximately seven species are distributed from north-western Europe to eastern Asia. All seven species occur also in China, with the center of diversity of species on the Qinghai - Xizang Plateau, four species are found only in China. Most species thrive in seasonally wet areas. All are dioecious getrenntgeschlechtig ( dioecious ).
• Oil willow ( Elaeagnus L., Syn: oleasters Heister ex Fabricius ): The approximately 45 to 90 species have a wide distribution area, it ranges from southern Europe to Asia and North America. In China alone, 67 species occur, of which 55 are just there. You have hermaphrodite flowers are monoecious or getrenntgeschlechtig ( monoecious ).
• Buffalo berries ( Shepherdia Nutt, Syn. Lepargyrea Raf. ): The approximately three species are found in northern and western North America. All three species are dioecious getrenntgeschlechtig ( dioecious ) and have to constantly leaves.

Use

The fruits of many species are edible. Therefore, Elaeagnus and Hippophae species are grown in many regions of the world or it is collected from wild plants. They contain very high levels of vitamin C. Some species are used as ornamental plants in parks and gardens used. Due to the nitrogen-fixing Frankia they can still thrive in poor soils. Therefore, some species, particularly Elaeagnus angustifolia used for reclamation.

Swell

• The Elaeagnaceae in APWebsite family. (Sections Description and systematics)
• The Elaeagnaceae at DELTA family. ( Description section )
• Haining Qin & Michael G. Gilbert: Elaeagnaceae, pp. 251 - text the same online as printed work, In: Wu Zheng -yi, Peter H. Raven & Deyuan Hong (eds.): Flora of China, Volume 13 - Clusiaceae through Araliaceae, Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 2007. ISBN 978-1-930723-59-7 ( section description)
• Y. Nasir: Elaeagnaceae in the Flora of Pakistan: Online. ( Description section )