Afrocarpus dawei
Afrocarpus dawei is a large conifer from the kind of yellow wood ( Afrocarpus ) in the family of Podocarpus plants ( Podocarpaceae ). The natural range is located in Africa in Tanzania and Uganda, where the species grows in temporarily flooded swamp forests. It is listed in the IUCN Red List as near threatened. The wood is used as timber and joinery.
- 6.1 Literature
- 6.2 Notes and references
Description
Afrocarpus dawei grows as evergreen, up to 33 feet tall with a long stem, the diameter of up to 100 centimeters ( diameter at breast height ) is reached. The Stammborke is dark brown, smooth under influence of weather and gray in young trees. For large trees, it is flaking off in small circular or rectangular scales. The branches are ascending and spread, forming a small, flat crown. The leaves grow close to numerous branches. Young side branches are more or less square in cross section and grooved.
Buds and leaves
Terminal buds are small, for example, have a diameter of 2 millimeters and can be absent. The bud scales are triangular or rounded, the tip may be geschnabelt.
The leaves of seedlings and young plants grow mostly against constantly and are narrowly linear - lanceolate, up to 17 centimeters long and 4-8 mm wide, straight or curved like a sickle and tapering to a fine point. Leaves of mature trees are shorter, usually 2 to 4 and sometimes up to 5 millimeters wide from only 2 usually 3 to 5 and sometimes up to 6 inches long and from 1.5. The leaves are spirally arranged and are spread or ascending. They are twisted at the base narrowed, so that the adaxial side down, gray-green, straight or only slightly curved sickle-shaped, linear - elliptic to linear, and run slowly or abruptly after three quarters of the length along the pointed upper end. The adaxial side has a distinctly protruding midrib. On both sides of the leaves numerous broken gap opening lines are formed, which are not clearly separated by the midrib.
Cones and seeds
The pollen cones grow singly or in twos to threes on short stalks or nearly often sitting in the leaf axils along with several papery bracts. They are initially rounded, extended later and are cylindrical at maturity, rarely 10 to 20 to 25 millimeters long with diameters of 2.5 to 3.5 millimeters. The Mikrosporophylle are spirally arranged, triangular to diamond-shaped, about 1 mm wide and have a serrated edge and a pointed - ausgebissenen or bespitztes end. The sporophyll two roundish pollen sacs are formed.
The seed cones grow individually on narrow, scaly or leafy branches into or under the leaf axils. They consist of several barren and a larger, terminal and fertile Deckschuppe. Sophisticated Samanzapfen have a single seed that grows over a single, small Deckschuppe. The seed is surrounded by a solid, fleshy Epimatium which to glaukgrün from green to yellow when ripe and discolored. It is then rounded and 25 to 35 millimeters long. The actual seed is flattened ovoid and slightly to the side, 16 to 21 millimeters long and 12 to 15 millimeters wide. The surface is wrinkled and hard, the seed coat 2-4 mm thick.
Distribution and ecology
The natural range is in Tanzania in the provinces of Kagera and Mara and Uganda. There Afrocarpus dawei forms with other species, the dominant species during the rainy season flooded swamp forests that lie east and south of Lake Victoria at altitudes from 1100 to 1200 meters in slow-flowing streams. Most often you will find the way together with Baikiaea and minor species of the genus Mimusops.
Threats and conservation
Afrocarpus dawei was classified by the IUCN Red List as near threatened ( " Near Threatened " ) in 2011. The distribution area ( " extent of occurrence" ) with approximately 175,000 square kilometers and stocks that there are about 3200 square kilometers, both of which are too large to derive a risk thereof, also the influence of the people in the area of distribution is low. But it seems to have come from the use to a decline in stocks, which is estimated at over 20 percent.
Systematics and etymology
Afrocarpus dawei is a species in the genus of African yellow wood Afrocarpus, the family of the stone Yews ( Podocarpaceae ) is counted. It was first described in 1917 by Otto Stapf in the Flora of Tropical Africa as Podocarpus dawei ( basionym ). The species was by Christopher Nigel Page assigned to the newly established genus Afrocarpus in the Notes from the Royal Botanic Garden, Edinburgh 1989. Other synonyms of the species are Afrocarpus mannii subsp. dawei ( Stapf ) Silba Nageia mannii var dawei ( Stapf ) Silba and Podocarpus usambarensis var dawei ( Stapf ) Melville. James Eckenwalder sees the differences Afrocarpus falcatus as insufficient and the transitions as continuously in order to give the copies species status. He therefore sees the name Afrocarpus dawei falcatus only as a synonym for Afrocarpus.
The genus name derives from Latin Afrocarpus Afro- for " African" and carpus for " fruit" from. The name was given to the genus, to distinguish it from the name of the genus Podocarpus, from which it was removed. The specific epithet honors the botanist dawei Morley Thomas Dawe (1880-1943), who has the type specimen found.
Use
The wood of Afrocarpus dawei has high quality, the strains are very large and only form at high altitude branches. It is used as timber and joinery. The trees are selected individually, despite the temporary inaccessibility of the areas and precipitated. The wood is not exported but processed regionally. The species is not cultivated.