Podocarpaceae
Slim African Yellow Wood ( Afrocarpus gracilior )
The stone Yews ( Podocarpaceae ) are a family of plants conifers ( Coniferales ). The botanical name Podocarpus is composed of the Greek words pous, podos Foot and Carpus of fruit together, so " Fußfrucht " and refers to the seed-bearing " receptacle " of the mature from the " Epimatium " surrounded seeds of Podocarpus species.
- 5.1 Literature
- 5.2 Notes and references
Description
Vegetative characteristics
There are evergreen trees and shrubs. The trunk is usually straight and the branches are mostly horizontal. The largest species of the family is Podocarpus totara, whose greatest exemplar " Pouakani " is called and Mangapehi in the King Country, Southern Waikato is New Zealand, it has a trunk diameter of 388 cm, a height of 42.7 m and an estimated volume of 203.7 m³. Very contradictory statements there is the oldest specimens within the Podocarpaceae, one speaks of 700 to 800 years in some species, up to 1200 years. Since individual species do not thrive in the tropical lowlands, but in cooler higher altitudes, annual rings are formed with them, which can be counted to determine the age and use. Something special is Parasitaxus usta, it is the only known parasitic species within the Pinopsida; this New Caledonian species is parasitic on another type of the Podocarpaceae: Falcatifolium taxoides.
The usually spirally arranged or distichous leaves on the branches are rare needle-or scale-like as the better-known taxa of Pinopsida, it is usually a clear, flat, lanceolate to oval leaf blade available. In the genus Phyllocladus take place phylloclades leaves the task of photosynthesis, there are here foliaceous broadened branches ( short shoots ) that are lobed at the edge.
Generative features
They are monoecious ( monoecious ) or mostly dioecious ( dioecious ) getrenntgeschlechtig. The male cones usually look like kittens and contain many stamens. Each stamen has two pollen sacs. The pollen grains are usually winged. The standing on thin stems, female cones ( homologous with the inflorescences of angiosperms ) are usually greatly reduced and often consist of only a few fleshy complex Deck and seed scales. In some species sterile seed scales can be fused with the pin axis to a fleshy stalk area.
The female cones mature usually within a year. Often the wingless seeds are individually and are completely surrounded by a fleshy aril (as in the aril of the yew, hence the German name), he develops from the top - seed scales complex and is called " Epimatium ". In a few genera ( Saxegothea ) there are small cones with a few (two to 20) seeds. It also forms two seed leaves ( cotyledons ), each of which has two parallel vascular bundles.
Dissemination and development history
Fossils of Podocarpaceae are known from the Early Triassic intermediaries, also root fossils are known from the Triassic.
The family has its distribution primarily in tropical and subtropical mountain forests of the southern hemisphere. Your disjoint area largely coincides with the geological continent Gondwana. The centers of biodiversity are located in Australia, New Caledonia, Tasmania and New Zealand. In addition, there are species in Male Rhodesia and South America. The South American species are mainly found in the Andes. Some species also extend north of the Equator to Southeast Asia or the Philippines. The areas of the genus Podocarpus ( Podocarpus ) extend to the southern Japan and southern China within Asia or to Mexico in the New World, and there are also Nageia to southern China and southern India. Two genera are also in Africa, the widespread Podocarpus ( Podocarpus ) and the endemic African yellow wood ( Afrocarpus ). Two types are there in Cuba.
System
To the family of Podocarpus plants ( Podocarpaceae ) includes 18-19 genera and 170-200 species:
- Acmopyle Pilg. With only two endemic species: one in Fiji, the other in New Caledonia.
- African yellow wood ( Afrocarpus ( J.Buchholz & NEGray ) CNPage ): With six endemic in Africa and Madagascar species.
- Dacrycarpus ( Endl. ) de Laub. With nine species which occur between Myanmar and New Zealand
- Dacrydium Sol. ex Lamb. With 16 species which occur between Southeast Asia and New Zealand
- Falcatifolium de foliage. With five species from Malaysia to New Caledonia
- Halocarpus Quinn: With three species in New Zealand
- Lagarostrobos Quinn: Is a monotypic genus with the only kind: Lagarostrobos franklinii (Hook f ) Quinn
- Manoao colensoi ( Hook. ) Molloy
- Microcachrys tetragona Hook. f
- Parasitaxus usta ( viell ) de Laub. It is a parasitic Art
- Patagonian Yew ( Saxegothaea conspicua Lindl. )
- Sundacarpus amarus ( flower) C.N.Page
Here is also the genus Phyllocladus in the Podocarpaceae contain, according to molecular biological investigations it belongs here, some botanists regarded as a separate family Phyllocladaceae to. The difference to other genera are mainly photosynthetic organs: the actual leaves are reduced to scales, instead they have phylloclades.
Synonyms for Podocarpaceae Endl. are: Acmopylaceae Bobrov & Melikyan and Phyllocladaceae Bessey.
Use
Few species are used as ornamental plants; in tropical and subtropical areas in parks and gardens, a few species worldwide as house plants.
Some species have been used for timber, overexploited rather, so that their stocks are in decline. Many species are endangered. The hard wood of Dacrydium cupressinum is particularly beautiful and veneers will be made from this example. Lepidothamnus intermedius provides wood for boat building. The wood of Nageia nagi is versatile. From Phyllocladus species, Prumnopitys species and many Podocarpus species, the wood is utilized.
The " receptacle " and / or " Epimatium " by some Dacrydium species, Podocarpus species, Prumnopitys species and Microcachrys tetragona is eaten raw or cooked. The resin of some Dacrydium species is processed into chewing gum or beer-type beverages. From Prumnopitys taxifolia a beer -like drink is made from the milk juice. From Nageia nagi the leaves are eaten cooked and extracted from the seeds an oil both as food and for the industry. The bark of Dacrydium cupressinum contains tannin. From Phyllocladus types of dyes are prepared.