Hippophae rhamnoides, also known as sea-buckthorn, is a species of flowering plant in the family Elaeagnaceae, native to the cold-temperate regions of Europe and Asia. It is a spiny deciduous shrub. The plant is used in the food and cosmetics industries, in traditional medicine, as animal fodder, in horticulture, and for ecological purposes.
Description and biology
Hippophae rhamnoides is a hardy, deciduous shrub that can grow between 2 and 4 m high (between 7 and 13 ft). It has a rough, brown or black bark and a thick, grayish-green crown. The leaves are alternate, narrow and lanceolate, with silvery-green upper faces. It is dioecious, meaning that the male and female flowers grow on different shrubs. The sex of seedlings can only be determined at the first flowering, which mostly occurs after three years. The male inflorescence is built up of four to six apetalous flowers, while the female inflorescence normally consists of only one apetalous flower and contains one ovary and one ovule. Fertilization occurs solely via wind pollination, so male plants need to be close to female plants to allow for fertilization and fruit production.
The oval or lightly roundish fruits grow in compact grapes varying from pale yellow to dark orange. Individual fruits weigh between 270 and 480 mg and contain high amounts of vitamin C, vitamin E, carotenoids, flavonoids and health-beneficial fatty acids, as well as higher amounts of vitamin B12 than other fruits.
The plants have a very developed and extensive root system, and the roots live in symbiosis with nitrogen-fixing Frankia bacteria. The roots also transform insoluble organic and mineral matters from the soil into more soluble states. Vegetative reproduction of the plants occurs rapidly via root suckers.
Taxonomy
Hippophae rhamnoides is situated in the family Elaeagnaceae, in the order Rosales.
Hippophae rhamnoides is divided into eight subspecies: ssp. carpatica, caucasia, fluviatilis, mongolica, rhamnoides, sinensis, turkestanica and yunnanensis. These subspecies vary in size, shape, number of main lateral veins in the leaves and quantity and color of stellate hairs. They also have different areas of distribution and specific uses.
The genus name Hippophae originates from the Greek words hippo = "horse" and phaos = "to shine" and is due to the ancient Greek use of sea buckthorn leaves as horse fodder to make their coats shine more. The species name rhamnoides means "resembling the Rhamnus", referring to the buckthorn plant.
Distribution
Hippophae rhamnoides is native to the cold-temperate regions of Europe and Asia, between 27 and 69EN latitude and 7EW and 122EE longitude. These regions include the Baltic Coasts of Finland, Poland and Germany, the Gulf of Bothnia in Sweden, as well as coastal areas of the United Kingdom and the Netherlands. In Asia, H. rhamnoides can be found in the northern regions of China, throughout most of the Himalayan region, including India, Nepal and Bhutan, Pakistan and Afghanistan. It is found in a variety of locations: on hills and hillsides, valleys, riverbeds, along coastal regions, on islands, in small isolated or continuous pure stands, but also in mixed stands with other shrub and tree species. H. rhamnoides has also recently been planted in countries such as Canada, the United States, Bolivia, Chile, Japan and South Korea.
The current total acreage of H. rhamnoides is about 3.0 million ha worldwide. This number includes both wild and cultivated plants. Of these, approximately 2.5 million ha are situated in China (1.0 million ha of wild plants and 1.5 million ha in plantations), 20 000 ha in Mongolia, 12 000 ha in India and 3 000 ha in Pakistan. This makes China the largest agricultural producer of H. rhamnoides. Approximately 10 000 acres of the plant are planted in China each year for berry production as well as eco-environmental improvement. As of 2003, approximately 100 km of field shelterbelts were planted in Canada each year, and over 250 000 mature fruit-producing plants were grown on the Canadian prairies with an estimated annual fruit supply of 750 000 kg. Other countries that grow H. rhamnoides as an agricultural plant include for example Germany and France.
Composition
Fruit
Sea buckthorn fruit contains sugars, sugar alcohols, fruit acids, vitamins (C, E, and K), polyphenols, carotenoids, fiber, amino acids, minerals, and plant sterols. Species belonging to genus Hippophae accumulate oil both in soft parts and in seed of the fruit. Oil content in soft parts is 1.5–3.0%, while in seed this is 11% of the fresh weight. For the compositions of sea buckthorn oils, see article: sea buckthorn oil.