Knema bengalensis
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| Knema bengalensis | ||||||||||||
| WJde Wilde |
Knema bengalensis is one of only two species of the genus Knema in the nutmeg family known from two finds in 1957 and 1999. Both sites are in the Cox's Bazar district of the Chittagong division in Bangladesh .
description
Knema bengalensis is a medium-sized tree that blooms in December. The inflorescences of male plants sit on stems three to five millimeters long. The ten to twenty individual flowers are three to six millimeters long and sit on 9 to 13 millimeter long stems. The flower covers of the male flowers of Knema bengalensis are inverted egg or pear-shaped and split over about two thirds of their length. The 13 or 14 stamens have stamens that are as long as or shorter than the anthers. The petals have a slight fluff, the sepals have rust-colored hairs. Female flowers have not yet been found. The elongated lanceolate leaf blades are 15 to 30 inches long and at the widest point in the middle 2.5 to 5.5 inches wide. They are thin and leathery, in the lower area densely covered with 0.3 to 0.5 millimeter long hair, and in addition to the slightly protruding central rib 20 to 28 also have protruding pairs of nerves. Their upper side is olive, the underside gray. The leaf stalks are 15 to 18 millimeters long, with a diameter of two millimeters. The branches are usually thin to a little strong with a diameter of two and a half to three millimeters at the tips. The bark of young twigs is smooth, that of older twigs is slightly striped, but not cracked or flaky. If the trunk is injured, a blood-red resin appears.
Knema bengalensis is closely related to Knema globularia used differs however from this species by the longer stamens, which do not at the base of the flower sleeve , long are grown by the slightly larger male flower buds, the 9 to 13 mm instead of 3 to 11 millimeters petioles and the fine and clearly protruding leaf veins. K. bengalensis differs from Knema linifolia in its less compact growth, the significantly smaller male flowers and the less strong leaf veins. Knema erratica has more striped branches and a different pattern of leaves. Their male flowers are very similar, but mostly forked deeper.
distribution
The type location of Knema bengalensis is Dulahazara ( 21 ° 39 '0 " N , 92 ° 4' 0" O ) in the district of Cox's Bazaar the Division Chittagong in the far south-east of Bangladesh . There the species was found on December 31, 1957 by the Bangladeshi botanist Mohammad Salar Khan from the University of Dhaka at an altitude of less than 200 meters above sea level on the edge of an evergreen mixed forest. A single other find succeeded Khan in December 1999 in the Upper Rezu Reserve Forest near Ramu ( 21 ° 26 ′ 0 ″ N , 92 ° 7 ′ 0 ″ E ), also in the district of Cox's Bazar.
Hazard and protection
The IUCN has Knema bengalensis in their published 1998 Red List of globally threatened species as endangered (category VU - Vulnerable ) classified. The reason given was the occurrence at a single location and the small size of the population. Since then, the species has not been reassessed by the IUCN. With targeted searches, the species could not be found either at the type location or at the second location since 1999. All protective measures are dependent on the recovery of both sexes of the species. If this succeeds, measures to protect the habitat as well as conservation breeding in botanical gardens are required.
Systematics
In its first description, Kema bengalensis was placed in the Obovoideae series with ten other species of the genus Knema because of the shape of the male flower buds . The genus Knema is distributed with more than 90 species from India to western New Guinea . It is one of the larger genera within the pantropically widespread nutmeg family (Myristicaceae), which has more than 500 species, mostly small to medium-sized trees in over twenty genera.
Initial description
The first description was made in 1979 by the Dutch botanist Wilhelm de Wilde in his revision of the species of the genus Knema recorded outside of Malesia . Knema bengalensis was described from a specimen and accompanying notes that were collected in December 1957 by the Bangladeshi botanist Mohammad Salar Khan. This male holotype is in the botanical collection of the Bangladesh National Herbarium in Dhaka , according to other sources in the collection of the University of Edinburgh . The species name bengalensis refers to the Bengal region , the eastern part of which is Bangladesh.
Web links
Individual evidence
- ↑ a b W.JJO de Wilde: New account of the genus Knema (Myristicaceae) . In: Blumea 1979, Volume 25, No. 2, pp. 321-478, here p. 333, digitized .
- ↑ a b c d W.JJO de Wilde: New account of the genus Knema (Myristicaceae) , pp. 413-414.
- ↑ WJJO de Wilde: Additional notes on species of the Asian genera Endocomis, Horsfieldia, and Knema (myristicaceae) . In: Blumea 1996, Volume 41, No. 2, pp. 375-394, digitized .
- ↑ a b c M. K. Pasha: An Evaluation of Endemism and Endemics in Bangladesh Flora . In: Eivin Røskaft and David J. Chivers (Eds.): Proceedings of the International Conference on Biodiversity - Present State, Problems and Prospects of its Conservation. January 8-10, 2011. University of Chittgaong, Chittagong 4331, Bangladesh . University of Chittagong 2012, pp. 57-76, ISBN 978-82-998991-0-9 .
- ↑ WJJO de Wilde: New account of the genus Knema (myristicaceae) , S. 344th
- ↑ a b c M. Atiqur Rahman and M. Enamur Rashid: Status of endemic plants of Bangladesh and conservation management strategies . In: International Journal of Environment 2013, Volume 2, No. 1, pp. 231–249, doi: 10.3126 / ije.v2i1.9224 .
- ^ Sara Oldfield, Charlotte Lusty and Amy MacKinven: The World List of Threatened Trees . World Conservation Press, Cambridge 1998, p. 304, digitized .
- ↑ WJJO de Wilde: Myristicaceae. Flora Malesiana. Series I, Volume 14 . Nationaal Herbarium Nederland, Leiden 2000, ISBN 90-71236-47-1 , doi: 10.3897 / ab.e1141 , pp. 1–27.