Yellow horse chestnut
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Yellow horse chestnut ( Aesculus flava ) |
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The yellow horse chestnut ( Aesculus flava ), also called Appalachian horse chestnut or yellow pavie, is a species of horse chestnut ( Aesculus ). It is widespread in North America, where it is the largest and most important horse chestnut species in terms of forestry.
description
Vegetative characteristics
The yellow horse chestnut is a large tree that reaches heights of 20 to 30 meters and a trunk diameter of up to 1.5 meters. The young bark is brown-gray, later gray, heavily furrowed and broken into large scale plates, the surface is further roughened by many small scales. The twigs are initially orange-brown, later gray-brown, smooth or gray-haired. The buds are blunt, the scales of the buds have a round back, are pointed briefly and ciliate on the edge. The leaf scars are large with numerous vascular bundle scars that form a triangle.
The leaves are divided into a petiole and a leaf blade. The petiole is 8 to 19 cm long, glabrous to hairy. The finger-pinnate leaf blade has five to seven leaflets. The leaflets are 10 to 21 centimeters long and 4 to 8 centimeters wide and obovate-oblong to elliptical-obovate. The end of the leaf is pointed, the base of the leaf wedge-shaped. The leaf margin is sawn more or less evenly. The upper side is dark green, glabrous or bald, the underside is dull, glabrous with few hairs on the nerves or also densely hairy. The leaflet stalks are 2 to 3 mm long, glabrous to hairy.
Generative characteristics
The inflorescence is elongated and downy hairy at a length of 10 to 15 centimeters. The flower stalk is 4 to 8 mm long, glandular, with the glands up to 2 mm long and black. The longer glands of the pedicel are often located in the lower third of the calyx. The five calyx lobes are rounded or truncated.
The flowers are somewhat zygomorphic . The calyx is 7 to 10 mm long, bell-shaped to tubular-bell-shaped, glandular-downy hairy on the surface, shaggy on the edge. The corolla is pale to strong yellow, the nail deep dark yellow, which changes to reddish brown during flowering. The crown consists of four unequal petals, the nails are shaggy and curled at the tip, the plates are glandular-downy-haired on the surface, shaggy on the edge. The upper petals are 20 to 30 mm long, their nail 16 to 25 mm, the plate is small and spatulate. The lateral petals are 16 to 25 mm long, their nail 8 to 15 mm, longer than the calyx, the plate is obovate to round with a slightly heart-shaped base. The 7 or 8 stamens are 15 to 20 mm long. The stamens are straight or curved, the lower half shaggy. The anthers are glabrous and glandular at the tip and base of the loculi. The pistil is equal to or longer than the lateral petals and with the exception of the stigma shaggy hair.
The capsule fruit is approximately spherical with a diameter of 5 to 8 centimeters. The pericarp is thin or thick, smooth or slightly pitted, and light brown in color. The fruit contains one to three, rarely four to six seeds of a maroon color with a large, pale stigma .
The number of chromosomes is 2n = 40.
Distribution and locations
The distribution area of the yellow horse chestnut stretches from southwest Pennsylvania along the Ohio River to Illinois , the trees rarely grow further than a kilometer from the river. The area includes southeast Ohio, West Virginia, eastern Kentucky, the Cumberland Mountains, the Tennessee Plateau and northeast Alabama, the Appalachian Mountains in Virginia, the Carolinas and northern Georgia to the south. Find reports from Texas and Iowa are based on incorrect determinations of Aesculus glabra and yellow forms of Aesculus pavia . The northern limit of distribution on the Ohoi River correlates strongly with the icing limit of the last ice ages. There is no current limit due to climate or soil factors. The border is probably due to the Pleistocene glaciation, Aesculus flava cannot expand significantly to the north. The distribution area is much smaller than that of Aesculus glabra or Aesculus pavia , Aesculus flava also does not show their great variability.
The yellow horse chestnut is a typical part of the mixed mesophytic societies of the East American deciduous forests. It is particularly common in the Liriodendretalia forests. It is often dominant, even more often codominant with Tilia heterophylla , Liriodendron tulipifera and Acer saccharum .
Taxonomy
Aesculus flava was first published in 1778 by Daniel Carl Solander in J. Hope: Catalogus Arborum et Fruticum in Horto Edinensi Crescentium Anno 1778 , 1. One of many synonyms for Aesculus flava Sol. is Aesculus octandra Marsh.
use
Along with Aesculus glabra, the yellow horse chestnut is the only forest species of the genus Aesculus in North America. The wood is used to make furniture, boxes and tools.
supporting documents
- James W. Hardin: A Revision of the American Hippocastanaceae II. Brittonia, Volume 9, 1957, pp. 173-195.
Individual evidence
- ↑ a b Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 . Se. 648.
- ↑ Schütt , Schuck, Stimm: Lexicon of tree and shrub species. Nikol, Hamburg 2002, ISBN 3-933203-53-8 , p. 30.
Web links
- Area map (United States Geological Survey; PDF file; 682 kB)
- Information and photos about the yellow horse chestnut at baumkunde.de .
- photos