Phyllocladus hypophyllus

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Phyllocladus hypophyllus
Illustration by Phyllocladus hypophyllus [1]

Illustration of Phyllocladus hypophyllus

Systematics
Subdivision : Seed plants (Spermatophytina)
Class : Coniferopsida
Order : Conifers (Coniferales)
Family : Stonecaceae (Podocarpaceae)
Genre : Phyllocladus
Type : Phyllocladus hypophyllus
Scientific name
Phyllocladus hypophyllus
Hook.f.

Phyllocladus hypophyllus is a type of conifers from the genus of leaf disks ( Phyllocladus ) from the family stone disks (Podocarpaceae). It grows as a tree up to 40 meters high or as a shrub at higher altitudes. Like all representatives of the genus,it forms phyllocladia , i.e. shoots that are shaped like leaves and also take on their tasks. The actual leaves are small, needle-shaped and only 2 to 5 millimeters long on older trees. The phyllocladia, on the other hand, can reach a length of up to 13 centimeters. The main distribution area is on Borneo , New Guinea and the Philippines , there are other occurrences on the Moluccas and Sulawesi . The wood is similar to that of stone slices , is used in many ways, but has almost only local significance.

description

Phyllocladus hypophyllus in the San Francisco Botanical Garden

The species forms shrubs or trees up to 40 meters high . In high forests it forms knotless trunks up to a height of 20 meters and more and chest height diameters of up to 100 centimeters, but usually remains thinner. The bark is up to 25 millimeters thick and forms numerous large warty cork pores . The bark of older trees is scaly, dark brown and, when exposed to the weather, dark gray to black. It flakes off in small to medium-sized scales and then releases the inner bark. The bark is red or pink near the wood and slightly fibrous. The branches are horizontal or ascending and, depending on the location, form a narrow to wide crown. The leafy branches are usually straight, stem-round, strong and smooth. They are spread out at an angle of less than 90 °. Young shoots are tinged red, later green and then light brown and end in a short bud with spreading, triangular to needle-shaped scales. The actual leaves on seedlings are sub-linear, pointed, 5 to 10 millimeters long and 0.5 to 0.7 millimeters wide. They have a central vein and stomata on the underside . The leaves of young trees are 2 to 5 millimeters long, sloping and develop at the base and on the edges of the phyllocladia . The phyllocladia grow in the axils of not fully developed, sloping, needle-shaped scale leaves, singly or in pairs to five, in a ring on long shoots. They are alternately pinnate in five to ten segments, flattened on both sides, leaf-like, very variable in size and shape, 1 to 13 centimeters long, 0.5 to 5 centimeters wide and usually rhombic in outline, less often parabolic or lanceolate. They have entire margins or have a partially deeply notched or, in the case of seedlings, deeply lobed edge and converge to form a stalked base. The phyllocladia carrying the seed cones are smaller, irregularly dissected, only slightly lobed, often wedge-shaped or deeply marginalized. A central vein runs from the base of the individual phyllocladia segments to near the tip, from which a few to many almost parallel side veins extend, which can be slightly bent outwards. Just sprouting phyllocladia are yellowish green, red or rust brown, later light green or red to copper colored and sometimes glaucous . Fully grown phyllocladia are glossy deep green or dark green on top, pale green and sometimes glaucous on the underside. On the underside, numerous stomata are arranged in irregular lines.

Phyllocladus hypophyllus is usually dioecious . The male pollen cones grow in groups of usually two to eight, sometimes up to 15, on branches that extend from the base of young shoots or from a terminal bud. Each individual cone grows on a 5 to 25 millimeter long stem, at the base of which a band-shaped, dry-skinned cover scale grows. Several phyllocladia and two small cover scales sometimes grow at the base of the cones. The cones are cylindrical, 10 to 15 millimeters long, with a diameter of 2.5 to 5 millimeters, in the immature state pink or reddish and later yellow. The microsporophylls are ovoid-triangular, often pointed and have two round pollen sacs at the base. The female seed cones grow individually, in twos or threes in the axils of not fully developed scale sheets on the edge or in a bulge at the tip of a phyllocladium, or on terminal branches without phyllocladia. They are 5 to 10 millimeters long, with a diameter of 2.5 to 4 millimeters. Each seed cone consists of five to 15 cover scales, one to three of which are fertile and grow together to form a red or purple-colored, 5 to 7 millimeter long dome-like structure that later swells a little and turns bright red. When dry it is leathery brown. For each fertile wrapper a single seed is formed, each of which is covered by a white or yellow aril about halfway. The seeds are hard, 5 to 7 millimeters long, semi-ovate (laterally flattened), and have a small protrusion at the tip. When ripe, they are glossy light brown or maroon brown.

Distribution and ecology

The natural range of Phyllocladus hypophyllus is in Borneo , the Moluccas , the Philippines , Sulawesi and New Guinea .

Phyllocladus hypophyllus grows in the lower montane to subalpine evergreen rainforest at altitudes of 600 to 3400 meters. There are smaller stocks at heights from 310 meters and up to 4000 meters. The distribution area is assigned to the hardiness zone 10 with mean annual minimum temperatures between −1.1 and +4.4 ° C (30 to 40 ° Fahrenheit ). In lower altitudes the species reaches the greatest stature heights. In Kerangas , for example, it forms the top layer of the crown on white sand made of sandstone with various types of Kauri trees ( Agathis ), or in mixed forests with representatives of the stone slab family (Podocarpaceae), the beech family (Fagaceae) and the laurel family (Lauraceae). In the higher-lying cloud forest or in low, only up to 20 meters high and heavily moss- covered forests, the trees of the species are heavily overgrown with ferns and mosses as epiphytes . It dominates these forests together with different types of resin ( Dacrydium ), warthog ( Dacrycarpus ) and stone ( Podocarpus ) or they are mixed forests. In New Guinea, the pseudo-beech Nothofagus grandis is often the dominant species, alongside which Phyllocladus hypophyllus and various representatives of the stone beech family (Podocarpaceae) can be found. In even higher altitudes, the forests are only low, the species then grows shrub-like, often on the edge of moist meadows. Phyllocladus hypophyllus grows on a variety of soils, such as those made of granite , serpentine or sandstone , on peaty soils, on weathered limestone or on volcanic subsoil.

Hazard and protection

Phyllocladus hypophyllus was classified as Least Concern by the IUCN in the Red List in 2014 . The species is widespread and common in its range. However, it is often felled together with other representatives of the stone slab family (Podocarpaceae) and stocks are declining in these areas. In many areas, especially in the Philippines, stocks are also being lost to deforestation. At higher elevations, the trees are smaller and both felling and deforestation have little or no impact. There are also protected areas in all states where the species is found. Overall, the stocks are declining, but this does not justify any other classification.

Systematics and research history

Phyllocladus hypophyllus is a species from the genus of the leaf disks ( Phyllocladus ) in the family of the stone disks (Podocarpaceae). The species was first described in 1852 by Joseph Dalton Hooker in Icones Plantarum . The type specimen comes from Kinabalu on Borneo, the highest mountain in Malaysia , where the species occurs frequently and over a wide range of heights. Synonyms are Phyllocladus hypophyllus var. Protractus Warb. , Phyllocladus major  Pilg. , Phyllocladus protractus  (Warb.) Pilg. and Podocarpus hypophyllus  (Hook.f.) Kuntze .

Due to the wide distribution there are clear differences between the individual specimens, especially in the shape of the phyllocladia, but also in the amount of wax on their underside. The representatives from the three main distribution areas on Borneo, New Guinea and the Philippines are therefore sometimes assigned to three separate species. But there are also clear differences between the trees in the respective areas, they assume a similar extent, so that most botanists seem to justify the assignment to a species.

The generic name Phyllokladus refers to the phyllocladia , i.e. the branches that have been transformed into leaf-like organs. It is derived from the Greek phyllos "leaf" and klados "branch" or "shoot". The specific epithet hypophyllus also comes from the Greek, hypo means "below" and phyllus "leafy", although it is unclear why Hooker chose this expression.

use

Phyllocladus hypophyllus rarely grows as a large tree, so the wood is only of local importance. In Papua New Guinea , it is even forbidden to export the wood as round wood, i.e. without processing it in sawmills, in order to support one's own economy. The wood is similar to that of stone slices ( Podocarpus ), it has a fine texture and is easy to work with. It is used as lightweight construction timber , for making floors and, to a lesser extent, for making furniture. In the past, the resin was also extracted and used. The bark is used to make roofs in New Guinea, and the phyllocladia are used to make tea in Borneo. The species is rarely cultivated, mostly only in botanical gardens.

Individual evidence

  1. ↑ Illustration from Louis van Houtte : Flore des serres et des jardins de l'Europe , 1858.
  2. ↑ a b c d Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 546.
  3. ↑ James E. Eckenwalder: Conifers of the World , p. 367.
  4. ↑ a b c d e James E. Eckenwalder: Conifers of the World , p. 368.
  5. ^ A b Aljos Farjon: A Handbook of the World's Conifers. Volume 2, pp. 546, 547.
  6. ↑ Phyllocladus hypophyllus in the endangered Red List species the IUCN 2014 Posted by: A. Farjon, 2011. Accessed March 9, 2015.
  7. ↑ Phyllocladus hypophyllus in the Germplasm Resources Information Network (GRIN), USDA , ARS , National Genetic Resources Program. National Germplasm Resources Laboratory, Beltsville, Maryland.
  8. ^ Phyllocladus hypophylla. In: The International Plant Name Index. Retrieved March 9, 2015 .
  9. ^ Joseph Dalton Hooker (Hook.f.): Phyllocladus hypophyllus . In: Icones Plantarum; or Figures, with Brief Descriptive Characters and Remarks of New or Rare Plants . London 1852, p. 889 ( online at Botanicus.org [accessed March 11, 2015]).
  10. ^ Phyllocladus hypophyllus. In: The Plant List. Retrieved March 9, 2015 .
  11. ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 544.
  12. ^ Aljos Farjon: A Handbook of the World's Conifers. Volume 2, p. 547.

literature

  • Aljos Farjon: A Handbook of the World's Conifers . tape 2 . Brill, Leiden-Boston 2010, ISBN 978-90-04-17718-5 , pp. 544, 546, 547 .
  • James E. Eckenwalder: Conifers of the World. The Complete Reference . Timber Press, Portland, OR / London 2009, ISBN 978-0-88192-974-4 , pp. 367, 368 .

Web links

Commons : Phyllocladus hypophyllus  - Collection of images, videos and audio files