Brachylaena huillensis

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Brachylaena huillensis
Brachylaena huillensis

Brachylaena huillensis

Systematics
Order : Astern-like (Asterales)
Family : Daisy family (Asteraceae)
Subfamily : Carduoideae
Tribe : Tarchonantheae
Genre : Brachylaena
Type : Brachylaena huillensis
Scientific name
Brachylaena huillensis
O. Hoffm.

Brachylaena huillensis is a species of the genus Brachylaena within the sunflower family (Asteraceae). Various common names are usedfor this species in the countries of natural origin.

description

Appearance and leaf

Brachylaena huillensis grows as a shrub or small tree and usually reaches heights of 7 meters, under favorable conditions heights of 30 to 35 meters and breast diameter (BHD) of 0.5 to 0.85 meters. The tribes are often grooved, curved and spannrückig , this makes it difficult to obtain large timber lengths. The trunk is free of knots up to about 8 meters. The gray bark is smooth or rough with cracks. The dark gray bark is finely cracked longitudinally and flakes off in strips. The bark of the twigs is initially grayish or brown with woolly hairs, later becomes bald, becomes dark purple in color, has lenticels and is closely furrowed.

Brachylaena huillensis is evergreen in areas with humid climates and deciduous in dry areas. The alternate, often upper at the ends of the branches heaped arranged leaves are divided into petiole and leaf blade. The petiole is 0.2 to 1.4 inches long. The simple, flat or more or less strongly downwardly curled leaf blade is usually 3 to 10, rarely up to 13 centimeters and a width of 1 to 3, rarely up to 4 centimeters narrow elliptical-inverted-lanceolate to inverted- egg-shaped or elliptical to narrowly elongated-elliptical with wedge-shaped base, pointed to rounded upper end, which is clearly prickly. The leaf margin is usually smooth; rarely it is more or less spiky-toothed with obovate leaf blades, especially in the direction of the leaf tip. In the undergrowth the leaf blades are slightly larger. The glossy, matt green upper side of the leaf is initially thin, cobweb-like and balding early with recognizable network nerves. The underside of the leaf is grayish or silvery woolly hairy with raised leaf veins . There are no stipules .

Inflorescence, flower and fruit

Brachylaena huillensis is dioecious, separate sexes ( diocesan ), with the inflorescences of female and male specimens clearly different. The cup-shaped partial inflorescences stand together in terminal or lateral, woolly hairy, ear-like , racemose or almost spherical total inflorescences . The flower heads only contain tubular flowers . The male flower heads have a short stalk at most and contain six to seven flowers. Their involucrum is goblet-like with a length of up to 3 millimeters, the bracts enlarge from the outside to the inside from ovoid with a length of about 1 millimeter to about 3 millimeters and elongated. Its cream-white tubular flowers are 3.5 to 5.5 millimeters in length, narrow-funnel-shaped with about 2 millimeters long and more or less curved back crown teeth. The female flower heads are stalked and contain five to six flowers. Their involucre is cylindrical-inverted-conical with a length of up to millimeters, the bracts enlarge from the outside to the inside from a length of about 1 millimeter egg-shaped to about 5 millimeters and oblong. Their narrow tubular flowers are 4 to 6 millimeters long with upright crown teeth up to 0.5 millimeters long. The woolly hairy bracts are shorter than the flowers, hence the generic name Brachylaena , which means "short coat" or "cover coat".

The achenes, which are 3 to 4 mm long, are relatively small and hairy, almost cylindrical and indistinctly six to eight ribs. The pappus consists of several rows of bristles with a length of 4 to 5 millimeters more or less round peduncles, with their beards being more or less as wide as the length of the bristle axes.

Occurrence and endangerment

The natural range of Brachylaena huillensis is in tropical East Africa and in southern Africa . There are deposits in Kenya, Uganda, Tanzania, Angola, Mozambique, Botswana, Zimbabwe, Swaziland and in the South African provinces of KwaZulu-Natal, Limpopo and Mpumalanga.

Brachylaena huillensis occurs at low to medium altitudes . Brachylaena huillensis thrives in different forest types from highland semi-evergreen forest to coastal dry forest or in thickets. It is often found in coastal and dune forests and inland in deciduous forest edges or forests in erosion channels . There are sites on granite - or quartzite - outcrops . In Kenya it thrives in evergreen forests with flooded tree trunks. In southern and western Zimbabwe, it thrives on rocky sites of granite outcrops.

In Kenya and Tanzania in particular, there is heavy industrial logging and Brachylaena huillensis is one of the most widely used woods. Increased use in Mozambique will create a hazard. The populations in South Africa are safe and some stocks are in protected areas. Dense stocks have been reported from the northern parts of the Kruger National Park . In the IUCN Red List of Threatened Species in 1998, Brachylaena huillensis was rated as “near threatened”. The appendices of CITES will brachylaena huillensis not mentioned.

Taxonomy

The first description of brachylaena huillensis was made in 1902 by Karl August Otto Hoffmann in Botanical yearbooks for systematics, plant history, plant geography , Volume 32, page 149. The specific epithet huillensis refers to the place name Huilla in Angola. Synonyms of Brachylaena huillensis O.Hoffm. are Brachylaena hutchinsii Hutch. and Tarchonanthus camphoratus sensu here .

Common names

There are many trivial and trade names, some of them tribal, for Brachylaena huillensis . Depending on the area, the names laeveldvaalbos ( Afrikaans ), low veld brachylaena , low veld silver oak , silver oak ( English ), mkalambaki , mkarambati , muhugu , muhuhu and mvumo ( Swahili ) are used.

use

From brachylaena huillensis are essential oils (Muhuhuöl, African sandalwood) won that as a substitute for sandalwood serve.

Wood

Wood description

The freshly cut heartwood is light yellow-orange to olive-green-brown in color. Under the influence of air, the wood darkens to a yellow-brown, slightly greenish color. The sapwood differs significantly from the heartwood. The smell of Brachylaena huillensis is aromatic and similar to that of the sandalwood tree ( Santalum album ).

Technical data on wood

The average dry matter is 930 kg / m³. The fiber course is alternately twisted . A wavy or curled grain pattern is possible.

Parameter value unit
Bulk density 0.81-1.00 g / cm³
Compressive strength 7.2-8 N / mm²
tensile strenght k. A. N / mm²
Flexural strength 11.3-12.5 N / mm²

Wood properties

The wood of Brachylaena huillensis is heavy and very abrasion and shock resistant. It shows a high compressive strength , whereby it is not very impact-resistant and has average flexural strength . The suitability for steam bending is described as medium. Because of their relatively high density, tools dull moderately quickly and saw blades tend to gum up. The cutting angle when planing should be reduced. Brachylaena huillensis is easy to turn , stain , varnish and polish . Gluing is difficult and drilling should be done when nailing. The wood should be dried slowly to avoid cracks, with surface and brain cracks being typical drying errors .

Shelf life and use

The heartwood is moderately resistant to termites and bivalve molluscs . The wood is insensitive to rot . Treatment with wood preservatives is described as very difficult. Brachylaena huillensis is used as a resilient floor covering , wood carved and turned, road surface for bridges, railway sleepers , furniture and for heavy construction tasks. The use as heating material is also described.

Wood anatomy

The vessels are arranged with scattered pores. The vascular pits are alternate and have a vertical diameter of 2 to 3 µm. There are numerous tracheids and thick-walled fibers with fiber pits. The rays are almost exclusively single-row, consisting of one cell type. There are seldom double-row beams. There are neither intercellular canals nor crystals.

Health risks

As a health risk in dealing with brachylaena huillensis is dermatitis appears.

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Individual evidence

  1. ↑ a b c d e f g h i j k l m n o p q G. V. Pope: Compositae. In: Flora Zambesiaca , Volume 6, 1992: Brachylaena huillensis O. Hoffm. - Full text online.
  2. ↑ a b c d e f g h i Michael Finger: Muhuhu (Brachylaena huillensis). In: Holzwurm-page, wood with know-how. Retrieved November 25, 2013 .
  3. ↑ a b c d e f g Brachylaena huillensis. In: AgroForestryTree Database. International Center for Research in Agroforestry (ICRAF), accessed on February 6, 2014 . PDF.
  4. ↑ a b data sheet at Africa Tree Database . ( Memento of the original from June 10, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved November 14, 2013. @1@ 2Template: Webachiv / IABot / www.africatreedatabase.com
  5. ↑ a b c d e f g Terry Porter: Recognizing and determining wood . 2nd Edition. HolzWerken, Hannover 2011, ISBN 978-3-86630-950-0 , p. 73 .
  6. ^ A b c H. G. Richter & MJ Dallwitz: Brachylaena hutchinsii Hutch. (Muhuhu). In: Commercial Timbers. May 4, 2000, accessed November 14, 2013 .
  7. ↑ a b c Brachylaena huillensis in the IUCN Red List of Threatened Species 2015.4. Listed by: World Conservation Monitoring Center, 1998. Retrieved February 23, 2016.
  8. ↑ a b c d Brachylaena huillensis in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland. Retrieved November 14, 2013.
  9. ↑ Alex O. Obara, Martina G. Höft, Robert Höft: Neem, Azadirachta indica A. Juss. (Meliaceae), and Its Potential for Sustainable Woodcarving in Kenya . In: Economic Botany . tape 58 , no. 1 , 2004, p. 98 .
  10. ^ CITES list. In: Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Retrieved February 23, 2016 .
  11. ↑ First publication scanned at biodiversitylibrary.org . (Issue 1 (pp. 1–208) was published on May 2, 1902. However, the volume was published in 1903. Therefore, the first-mentioned date is taken as the date of the first description.) Retrieved on November 14, 2013.
  12. ↑ a b Brachylaena huillensis at Tropicos.org. Missouri Botanical Garden, St. Louis. Retrieved November 14, 2013.
  13. ↑ Brachylaena huillensis in: Catalog of Life : October 17, 2013. Retrieved November 14, 2013.
  14. ^ John O. Kokwaro: Classification of East African Crops. Second Edition, Univ. of Nairobi Press, 2013, ISBN 978-9966-792-24-2 , p. 131.
  15. ↑ a b c d Alexander Liddon Howard: A Manual of the Timbers of the World; Their Characteristics and Uses . 3. Edition. Macmillan & Co. Ltd., London 1951, p. 375 .

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