Trachycarpus nanus
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Copy in the Botanical Garden in Düsseldorf |
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| Scientific name | ||||||||||||
| Trachycarpus nanus | ||||||||||||
| Becc. |
Trachycarpus nanus belongs to the subfamily Coryphoideae in the palm family (Arecaceae).
history
Trachycarpus nanus was discovered in 1887 by Father Delavay in the Chinese province of Yunnan , where it grows in the forests above Tapintze at altitudes of around 1800 meters.
The specimens in the herbarium of Paris show different phases of development of this palm species. There are some with male flowers that have not yet opened, which were collected at the beginning of April 1887, as well as those with female flowers in the high flowering stage, from April 27, 1887, some with developing ovaries, covered with silvery hairs, from June 2 1887, and finally some with half-ripe fruit from July 1888.
It was first described in 1910 by the Italian botanist Odoardo Beccari as Trachycarpus nana .
description
Trachycarpus nanus is a species related to the Trachycarpus fortunei and the Trachycarpus takil , but it differs greatly from both, mainly due to its inability to develop a larger above-ground trunk. It also distinguishes itself through its very deeply incised leaf segments and its inflorescences, which emerge from the ground directly between the leaves, and which form an elongated grape-shaped panicle, as well as the female flower, whose corolla is slightly larger than the calyx .
leaves
The leaves are similar to those of Trachycarpus fortunei , but are smaller and the leaf segments divide the leaf blade more deeply than any other Trachycarpus species. The leaf segments are stiff, with bluish frosting on the underside. The leaf segments divide the leaf up to a distance of 5 to 10 cm from the hastula . At their tips, the leaf segments are briefly divided into two, the tips being blunt.
Inflorescences and flowers
The inflorescences are stiff and erect, with only a few branches, which together form an elongated raceme-shaped panicle, twofold branched, with very short, flower-covered side branches that are hairless. Male and female inflorescences are very similar to each other, but the ramifications of the male inflorescences are less stiff and more delicate than in the female and completely covered with flowers, which are united in umbels of three, are very close together. They are equipped with tiny, pointed, brown, delicate and membrane-like bracts.
The male flowers are more or less spherical, about 2.5 mm in diameter and hairless. The sepals are fine and membrane-like, completely free and not overgrown, a little unequal in size, largely egg-shaped, blunt at the top or rounded, translucent and smooth at the edges. The petals are irregularly rounded, with smooth, slightly overlapping edges, twice as long as the sepals. Six stamens with short stamens (filaments), which do not protrude above the petals even during full bloom (anthesis). The anthers are elongated. The three small carpels are conically stretched, somewhat as wide as the filaments, hairless, half as long as the petals .
The female flowers are spherical and arranged in groups of three. They are very close together, but without pushing one another. The bracteoles are inconspicuous. During the flowering period, the flowers are spherical to ovate, 2.5 mm wide and 3 mm long. The sepals are very broad and ovoid, and only slightly shorter than the petals, blunt, and very close together at the base of the flower, where they are also somewhat thicker and coarser than at the top. They are smooth, rounded, or slightly rounded serrated on the back, with thin, sharp edges. The petals are ¼ to 1/5 longer than the sepals, otherwise very similar to these, very broadly ovoid, truncated at the top or almost round with smooth, hairless edges. The six staminodes (= sterile stamens) are slightly smaller than the petals, with compressed filaments and arrow-shaped anthers. three carpels , completely detached, ovate, and covered in the lower part with silvery hairs. In the upper part they are smooth and hairless, and there they gradually merge into a conical-pointed stylus that is not or only slightly inclined outwards, which has a fine furrow on the inside, and at the end of which there is a point-like scar. The ovule (ovary) is basal and anatrop .
Fruits and seeds
The fruits of the Trachycarpus nanus resemble those of the Trachycarpus takil more than the seeds of the Trachycarpus fortunei , and are distinctly kidney-shaped. Grooved on one side and constricted like an umbilicus at the point where the scar was. The seeds are 10 mm wide and 7 mm thick. The epicarp is very thin and smooth. The mesocarp is also only sparsely present. The seeds have the same external shape as the fruits. The embryo is not in the center of the convex side, as in the Trachycarpus fortunei , but is shifted somewhat laterally, as in the Trachycarpus takil . So if you split the seed lengthwise into two equal parts, the embryo would always stay on one side without ever touching the cut edge.
Chromosome number
The number of chromosomes is 2n = 36.
Care in Western Europe
The Trachycarpus nanus should basically have similar demands as Trachycarpus fortunei . There are some specimens that have been planted out for many years in the Düsseldorf agglomeration . The frost tolerance is not known. The plant is probably at least suitable for USDA climate zone 9a.
literature
- Odoardo Beccari: 1910, Descrizione di una nuova Spezie di Trachycarpus, Webbia III and V, 1920, page 70
- Odoardo Beccari: Asiatic Palms - Corypheae . Annals of the Royal Bot. Gard. Calcutta 13 - Calcutta 1933
- Giorgio Roster: Le Palme coltivate…, in Bull. Soc. Tosc. di Ortic., (1915)
- Chris Stührk: Molecular systematic studies in the subtribe Thrinacinae, with special consideration of the genus Trachycarpus H. Wendl. (Arecaceae), 2006.
- Image by and released by James Verhaegen, Europalms.Be
Individual evidence
- ↑ Trachycarpus nana at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
