Dyer's oak
| Dyer's oak | ||||||||||||
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Dyer's oak ( Quercus velutina ) |
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| Quercus velutina | ||||||||||||
| Lam. |
The Quercus velutina ( Quercus velutina ), also Quercitron oak or Black Oak called, is a plant from the genus of oak ( Quercus ) in the family Fagaceae (Fagaceae). As the common name of the dyer's oak suggests, it is a dyer's plant .
description
Appearance, bark and leaves
The dyer's oak grows as a deciduous tree that can reach heights of up to 25 meters. The tan or gray downy hairy terminal buds are egg-shaped or ellipsoidal to almost conical with a length of 6 to 12 mm, with a clear pentagonal cross section.
The deeply furrowed bark , which is often broken into irregular blocks, is dark brown to dark gray to almost black on the outside, but strikingly yellow to orange on the inside. Even in young trees, the bark tears open into small fields, and the yellow color underneath becomes visible. The bark of the twigs is rust-brown and hairless to sparsely hairy.
The alternate and spirally arranged leaves on the branches have a length of 12 to 25 cm and are divided into a petiole and a leaf blade. The 2.5 to 7 cm long petiole is hairy bald to sparsely downy. The simple one with a length of (rarely 8 to) 10 to 30 cm and a width of 8 to 15 cm ovate to obovate leaf blade with an unequal, blunt to clipped blade base has five to nine leaf lobes with deep indentations and 15 to 50 attached , awn-like tips on the leaf margin. The main nerves stand out clearly on the light green underside of the leaf, there it is somewhat hairy, otherwise it is bare. The dark green upper side of the leaf is bare and the main nerves also emerge here.
Generative characteristics
The dyer's oak is single-sexed ( monoecious ).
With a height of 7 to 14 mm and a diameter of 12 to 22 mm, the cup- to top-shaped fruit cup (cupula) is hairy on the outside and envelops half of the glans. The bald acorn ( nut fruit ) that remains on the tree over the winter is almost spherical to ovoid with a length of 1 to 2 cm and a diameter of 1 to 1.8 cm.
The basic chromosome number is n = 12 ± 1 and the diploid chromosome set is 2n = 24.
distribution
The distribution area of the dyer's oak is in eastern North America . It is found primarily in southern New England and central states such as Pennsylvania , Georgia , South and North Carolina . It mainly thrives on dry slopes and plateaus at altitudes between 0 and 1500 meters.
Systematics
The species name Quercus velutina was first published by Jean Baptiste de Monnet de Lamarck in J. Lamarck et al .: Encyclopédie Méthodique, Botanique , 1, 1785, p. 721. A synonym for Quercus velutina Lam. is Quercus tinctoria W.Bartram. Quercus velutina belongs to the Lobatae section in the genus Quercus .
Quercus velutina forms hybrids with Q. coccinea , Q. ellipsoidalis (= Q. × paleolithicola Trelease), Q. falcata [= Q. × willdenowiana (Dippel) Zabel and Q. × pinetorum Moldenke)], Q. ilicifolia (= Q. × rehderi Trelease), Q. imbricaria (= Q. × leana Nuttall), Q. incana , Q. laevis and Q. laurifolia (= Q. × cocksii Sargent; the information from EJPalmer 1948 for the hybrids with Q. marilandica , Q. nigra , Q. palustris (= Q. × vaga EJPalmer & Steyermark), Q. phellos (= Q. × filialis Little), Q. rubra , Q. shumardii and perhaps Q. arkansana .
use
The bark of the dyer's oak is used for dyeing , but has also been used as a color varnish in painting throughout history . The yellow dye is the flavone quercetin (= pentahydroxyflavone); it is obtained from the inner bark . In trade , the ground bark under the name "Quercitron" (which was made Quercus for oak and citrina for yellow was composed) sold. It was used to dye leather.
The indigenous peoples of North America used the dyer's oak in their folk medicine .
swell
- Kevin C. Nixon: Quercus. In: Flora of North America. Volume 3, 1997, online (section description, distribution and systematics).
