Tenon socket

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Tenon socket
Platycarya strobilacea3.jpg

Cone nut ( Platycarya strobilacea )

Systematics
Rosids
Eurosiden I
Order : Beech-like (Fagales)
Family : Walnut family (Juglandaceae)
Genre : Platycarya
Type : Tenon socket
Scientific name of the  genus
Platycarya
Siebold & Zucc.
Scientific name of the  species
Platycarya strobilacea
Siebold & Zucc.

The cone nut ( Platycarya strobilacea ) is a species of the plant genus Platycarya within the walnut family (Juglandaceae). It is native to East Asia. Within the family, it stands out for its cone-shaped fruit stands with stiff, woody bracts .

Description and ecology

Illustration from Flora Japonica
Habitus

Vegetative characteristics

Platycarya strobilacea grows as a deciduous tree or large shrub and reaches heights of up to 15 meters. The pith of the branches is firm. Terminal buds are broadly ovate to almost spherical and have broad, overlapping bud scales. A characteristic in wood that is unusual for the family is the spiral thickening of the secondary cell walls of trachea and tracheids .

The alternate leaves arranged on the branches are divided into a petiole and a leaf blade. The petiole is 1.2 to 9.2 inches long and glabrous. The leaf blade is 8 to 30 centimeters long and pinnate unpaired . The rhachis leaf is also bare. The foliage leaf consists of 1 to 15, rarely up to 23 leaflets with a serrated edge. The lateral leaflets sit on the rachis and have an ovate-lanceolate to narrow elliptical-lanceolate shape. They are 3 to 11 inches long, 1.5 to 3.5 inches wide, and glabrous on the underside, with the exception of dense tufts of hair at the base and along the midrib. The terminal leaflet is stalked 0.6 to 3.5 centimeters long. There are no stipules .

The germination takes place epigeal. The cotyledons are leaf-like and have four lobes. The first true leaves of the seedling are simple, they are followed by pinnate ones. The knot of the cotyledons has a lacuna and two leaf tracks.

Generative characteristics

The flowering period in China extends from May to July. Platycarya strobilacea is single sexed ( monoecious ), male and female sexual organs are in separate flowers , but on one plant specimen. The inflorescences are formed terminally on this year's shoots. They stand upright and are androgynous panicles composed of male and female ears . The inflorescences are contracted and resemble cones. The males are mainly to the side, the central ear is female with a male tip, rarely also completely male. The central ear is 2 to 10 centimeters long, the male 2 to 15 centimeters long. The flowers are pollinated by insects ( entomophilia ). The male flowers have an undivided bract , Brakteolen also missing as sepals . There are 4 to 15 stamens with glabrous anthers . The pollen grains have a pair of furrowed pseudocolpi in each hemisphere: fold-like thinnings of the pollen wall ( exine ). This characteristic is unique among the opulent . The pollen is small at 15 to 16 micrometers and triangular in polar view. The female flowers have an undivided, straight or bent back cover sheet that is not fused with the ovary , and two bracteoles that are fused with the ovary. Two sepals are fused with the bracts. One stylus is missing, the stigma is keeled, bilobed and short.

The fruit stand is ovate-ellipsoidal or ellipsoidal-cylindrical to almost spherical. It is 2.5 to 5 inches long and 2 to 3 inches wide. The bracts are lanceolate, 4 to 10 mm long and 2 to 3 mm wide. They are rigid and lignified and remain on the tree. The nuts have two wings that have developed from the bracts and are almost spherical to obovate and 3 to 6 by 3 to 6 mm in size. The fruits ripen between July and October and are spread by the wind.

There are different values for the number of chromosomes , but it is not the 2n = 32 typical for the family. The values ​​range from 2n = 22 to 2n = 28.

Occurrence

Platycarya strobilacea occurs in East Asia in China , Japan , Korea and Vietnam . In China it grows in mixed forests on mountain slopes, sometimes on limestone, at altitudes of 400 to 1400 meters, rarely up to 2200 meters.

Systematics and taxonomy

Platycarya has some unique characteristics within the walnut family in terms of wood, infructescence and chromosome number. It was therefore also regarded as a separate subfamily Platycaryoideae in the past. Molecular genetic studies, however, clearly placed Platycarya in the subfamily Juglandoideae, where they represent the basal group and the tribe Platycaryeae alone .

Platycarya strobilacea Siebold & Zuccarini (Syn .: Platycarya longipes Wu ; Plarycarya simplicifolia G.R. Long , Fortunaea chinensis Lindley ) was the only recent species of the genus Platycarya . But in 1999 another species was re-described:

Fossil, the group of the Platycaryeae is much more species-rich and has been documented since the Eocene . It is also found in fossil form in North America. Some examples:

  • Platycarya americana
  • Paleoplatycarya wingii

supporting documents

  • Anmin Lu, Donald E. Stone, LJ Grauke: Juglandaceae. : P. 278 - online with the same text as the printed work , In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (ed.): Flora of China. Volume 6: Caryophyllaceae through Lardizabalaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2001, ISBN 1-930723-05-9 .
  • Wayne E. Manning: The Classification within the Juglandaceae. In: Annals of the Missouri Botanical Garden , Vol. 65, 1978, pp. 1058-1087.
  • Paul S. Manos, Donald E. Stone: Evolution, Phylogeny, and Systematics of the Juglandaceae. In: Annals of the Missouri Botanical Garden , Volume 88, 2001, pp. 231-269.

Individual evidence

  1. a b c d e Anmin Lu, Donald E. Stone, LJ Grauke: Juglandaceae. : P. 278 - online with the same text as the printed work , In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (ed.): Flora of China. Volume 6: Caryophyllaceae through Lardizabalaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis 2001, ISBN 1-930723-05-9 .
  2. ^ Paul S. Manos, Donald E. Stone: Evolution, Phylogeny, and Systematics of the Juglandaceae. Annals of the Missouri Botanical Garden, Volume 88, 2001, pp. 231-269.
  3. Paul S. Manos, Pamela S. Soltis, Douglas E. Soltis, Steven R. Manchester, Sang-Hun Oh, Charles D. Bell, David L. Dilcher, Donald E. Stone: Phylogeny of Extant and Fossil Juglandaceae Inferred from the Integration of Molecular and Morphological Data Sets. In: Systematic Biology , Volume 56, 2007, pp. 412-430, doi : 10.1080 / 10635150701408523

Web links

Commons : Cone Nut ( Platycarya strobilacea )  - Album with pictures, videos and audio files