Eusideroxylon zwageri
| Eusideroxylon zwageri | ||||||||||||
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| Eusideroxylon | ||||||||||||
| Teijsm. & Binn. | ||||||||||||
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| Eusideroxylon zwageri | ||||||||||||
| Teijsm. & Binn. |
Eusideroxylon zwageri is a tree in the laurel family from Borneo and Sumatra . It is the only species in the genus Eusideroxylon .
Potoxylon melagangai (Syn .: Eusideroxylon melagangai ) is very similar , although the wood is a lot lighter, softer and much less durable.
description
Eusideroxylon zwageri grows as an evergreen , very slow-growing tree with a dense crown up to 40–50 meters high. The trunk diameter reaches 150-250 centimeters (up to 5.7 meters). Smaller buttress roots or corrugations are formed at the bottom of the trunk . The bark is red to gray-brown, slightly cracked and often flakes off in small plates or pieces. The trees can be over 1,000 years old.
The simple, leathery and short-stalked leaves are arranged alternately and helically. They are entire and ovate to elliptical, lanceolate or obovate. At the top they are pointed to pointed, on top they are bald and on the underside a little hairy on the veins. The short petiole is 6-15 millimeters long, the leaves about 14-18 centimeters. The stipules are missing. The young leaves are reddish.
Axillary, densely hairy, drooping and dense, paniculate inflorescences are formed. The stalked, fragrant and threefold, small flowers are hermaphroditic with a simple flower envelope . The 6 roofed tepals stand in two circles and are finely hairy on the outside. They are greenish, mostly yellow or purple in color. There are stamens and staminodes in 4 circles, only 3 stamens in the 3 circle are fertile, the staminodes are small and subphrate in the inner circle or tepaloid in the outer 2 circles. The unilocular ovary is half upper constant with a conical stylus with capitate, slightly lobed scar . There are small nectar glands present.
Round to egg-shaped or ellipsoidal, stone fruit-like, leathery-woody, slightly ribbed fruits (shell berries , false fruit ) are formed completely in the fleshy flower cup (meso-, exocarp ) with small flower remnants at the tip. They are brown to blackish and up to 7-16 centimeters in size. The ribbed, furrowed, brittle and light brown kernels (endocarp) are very large (up to about 14 centimeters) and hard, and the seeds, with a thin smooth seed coat and large cotyledons , are among the largest of the dicotyledons.
Taxonomy
The first description of the genus Eusideroxylon and the species Eusideroxylon zwageri was made in 1863 by Johannes Elias Teijsmann and Simon Binnendijk in Natuurk. Tijdschr. Ned.-Indië 25: 292. A synonym is Eusideroxylon borneense Fern.-Vill.
use
The very heavy, very durable, hard ironwood is very popular. It is known as Borneo ironwood , Belian, or Ulin .
The fruits and seeds are considered poisonous.
literature
- Bambang Irawan: Ironwood (Eusideroxylon Zwageri Teijsm. & Binn.) And Its Varieties in Jambi Indonesia. Dissertation, Univ. Göttingen, Cuvillier, 2004, ISBN 3-86537-320-8 .
- Klaus Kubitzki , Jens G. Rohwer , Volker Bittrich: The Families and Genera of Vascular Plants. Vol. II: Flowering Plants Dicotyledons , Springer, 1993, ISBN 3-540-55509-9 , pp. 366, 370, 378, 387.
- The Gardens' Bulletin, Singapore. 57, Part 1, 2005, p. 63 ff, online at biodiversitylibrary.org.
Web links
- Eusideroxylon zwageri on asianplant.net.
- Eusideroxylon zwageri at Useful Tropical Plants.
- Eusideroxylon zwageri at PROTA.
Individual evidence
- ↑ K. Ogata, H. Abe, P. Baas, T. Fujii: Identification of the Timbers of Southeast Asia and the Western Pacific. Kaiseisha press, 2008, ISBN 978-4-86099-244-6 , p. 166 f.
- ↑ Lan Qie, Alexander D. Elsy, Ashley Stumvoll et al .: Impending Regeneration Failure of the IUCN Vulnerable Borneo Ironwood (Eusideroxylon zwageri). In: Tropical Conservation Science. 12, 2019, doi: 10.1177 / 1940082918823353 .
- ↑ online at biodiversitylibrary.org.