Japanese sago palm fern
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Japanese sago palm fern ( Cycas revoluta ) |
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The Japanese sago palm fern or Japanese cycad ( Cycas revoluta ) is a type of cycad with leaves that are up to 180 centimeters long. It is the cycad most commonly used as an ornamental plant and is also cultivated in Mediterranean gardens, for example. However, its natural range is in Japan , natural stocks in China may have disappeared by now.
description
The Japanese sago palm fern forms a trunk up to 3, rarely 8 meters high, which can reach a diameter of 45 centimeters and rarely 95 centimeters. The trunk bark is black-gray and scaly. The 40 to 100 or more leaves are simply pinnate, 70 to 140 rarely to 180 centimeters long and 20 to 25 rarely to 28 centimeters wide. They are deep green and a little shiny. The petiole is more or less square in cross section, 10 to 20 centimeters wide and shows 6 to 18 spines along each side. The leaf blade is elongated-lanceolate to elliptical-lanceolate, clearly V-shaped in cross section and curved downwards. Young leaves are hairy brown tomentose. The leaflets grow in 60 to 150 pairs at an angle of 45 °. When fully grown, they are not glaucous , straight or more or less crescent-shaped, 10 to 20 centimeters long and 4 to 7 millimeters wide, leathery and sparsely hairy on the underside. The base of the leaflet is sloping, the edges strongly rolled down, the end pointed and piercing. The lower leaves are triangular, 4 to 5 centimeters long and 1.5 to 2.3 centimeters wide, densely tomentose hairy and pointed.
The Japanese sago palm fern is dioecious. The pollen cones are pale yellow, oval-cylindrical, 30 to 60 centimeters long and have a diameter of 8 to 15 centimeters. The microsporophylls are narrow wedge-shaped, 3.5 to 6 inches long and 1.7 to 2.5 inches wide. The megasporophylls of the female flowers are yellow to pale brown, 14 to 22 centimeters long, densely tomentose and have a 7 to 12 centimeter long stalk. The sterile leaves are ovate to narrowly ovate, 6 to 11 centimeters long and 4 to 7 centimeters wide, deeply slit with 21 to 35 1 to 3 centimeters long lobes. On each side of the stem two or three, densely pale brown and tomentose hairy ovules are formed. The mostly two to rarely five seeds are orange to red, obovate or ellipsoidal, somewhat compressed, from 3 mostly 4 to 5 centimeters long, 2.5 to 3.5 centimeters wide and sparsely hairy. They have a fleshy outer skin, a hard middle layer and a fleshy, floury nutrient tissue. Pollination takes place from May to July, the seeds ripen from September to October.
The number of chromosomes is 2n = 22, rarely 20.
Distribution and ecology
The natural range is in Japan on Kyūshū and the Ryūkyū Islands and in China in the province of Fujian . The species can be found in Japan from sea level to an altitude of 300 meters. It usually grows on steep to sloping, stony slopes on limestone cliffs or on rocks along the coast, but it used to occur in flat areas that have now been cleared. They are sometimes found in low, dense forests in very shady locations. In China, the Japanese sago palm fern grows in thickets mostly on offshore islands, less often on the mainland at an altitude of 100 to 500 meters.
Hazard and protection
The Japanese Sagopalmfarn was from in 2010 IUCN in the Red List as not threatened ( Least Concern classified). Although populations are declining across the range, the species is quite common in Japan and there are believed to be several hundred thousand specimens. The occurrences are considered stable. In China, it was widespread in the east of Fujian Province, but the stocks were heavily exploited and the habitat was destroyed. There were still isolated occurrences in the 1960s, but it is unclear whether there are still natural populations in China today.
Systematics and Etymology
The Japanese sago palm fern ( Cycas revoluta ) is a species from the genus of the sago palm ferns ( Cycas ), the only genus of the family Cycadaceae. It was first described by Carl Peter von Thunberg in 1782 as the second species of the genus Cycas . It differs from other species of the genus by the keeled, stiff deciduous leaves, the dense, stiff and narrow leaflets with the clearly downwardly curved edges and the felty hairy ovules. Synonyms of the species are Cycas inermis Oudem. , Cycas miquelii Warb. and Epicycas miquelii (Warb.) de Laub.
The generic name Cycas was chosen by Carl von Linné and is probably derived from the Greek koikas or in the singular koix , which referred to a palm tree from Egypt. The specific epithet revoluta comes from Latin and means "rolled back" or "rolled up" and thus refers to the leaflets that are bent down at the edges.
use
The Japanese Sago Palm Fern is the most commonly cultivated species of Cycads due to its appearance, winter hardiness and adaptability . It is often found, for example, as an ornamental plant in Mediterranean gardens. As with other sago palm ferns, all parts are poisonous. However, the seeds and stem can be detoxified by roasting and leaching and are then edible. The leaves have a high content of nitrogen compounds and are used as fertilizer on the Ryūkyū Islands. Dried and often colored leaves are made into wreaths or used as coffin decorations.
swell
literature
- Wu Zhengyi, Peter H. Raven, Deyuan Hong (Eds.): Flora of China . Volume 5: Ulmaceae through Basellaceae . Science Press / Missouri Botanical Garden Press, Beijing / St. Louis 2003, ISBN 1-930723-27-X , pp. 4 (English).
- Andreas Bärtels: Tropical Plants . Ornamental and useful plants. 5th, revised edition. Eugen Ulmer Verlag, Stuttgart 2002, ISBN 3-8001-3937-5 , p. 306 .
Individual evidence
- ↑ German name after Japanese sago palm fern (Cycas revoluta). In: online database for trees and shrubs. baumkunde.de, accessed on June 8, 2014 (German).
- ↑ German name after Bärtels: Tropical Plants , p. 58.
- ↑ a b c d e Dequan Lu, Michael G. Gilbert: Cycas revoluta , in Flora of China , Volume 4, p. 4.
- ↑ a b c Ken Hill: Cycas revoluta. In: The Cycad Pages. Royal Botanic Gardens Sydney, accessed June 8, 2014 .
- ↑ a b Bärtels: Tropical Plants , p. 58.
- ^ Tropicos. [1]
- ↑ Cycas revoluta in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
- ↑ a b Cycas revoluta in the endangered Red List species the IUCN 2013. Posted by: KD Hill, 2009. Accessed June 9, 2014.
- ↑ Cycas revoluta. In: The International Plant Name Index. Retrieved June 8, 2014 .
- ↑ Cycas revoluta. In: The Plant List. Retrieved June 8, 2014 .
- ↑ Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Nikol, Hamburg 2005, ISBN 3-937872-16-7 , p. 192 (reprint from 1996).
- ↑ Helmut Genaust: Etymological dictionary of botanical plant names. 3rd, completely revised and expanded edition. Nikol, Hamburg 2005, ISBN 3-937872-16-7 , p. 532 (reprint from 1996).
