Hat top layer
The hat skin , known in technical terms as the hat cover layer , is the uppermost hyphae layer of the mushroom hat . The scientific name is Pileipellis . It covers the hat meat or trama and protects it from external environmental influences. For example, the cap skin is less permeable to water than the other parts of the fruiting body. The term cutis (kutis) is also often used, especially when one wants to describe the macroscopic properties of the hat skin. If you want to describe the microscopic fine structure of the hat top layer, the term Pileipellis is mainly used .
The top hat layer also plays a role in identifying a fungus, as there are different types of top hat layers that differ microscopically but also macroscopically.
Types
Cutis
To a certain extent, the cutis represents the normal type of hat cover layer. The hyphae lie flat and parallel to the hat surface and are usually arranged radially. They are more or less interwoven with one another. Macroscopically, the cap skin usually appears smooth.
If the hyphae are short-celled and pseudoparenchymatic, the term epidermoid cutis is used. In many basidiomata with a cutis, a subcutis made up of less compact hyphae is formed between this and the hattrama.
Ixocutis
The ixocutis has a similar structure, but here the hyphae are gelled. The gelatinous substance in which the hyphae are embedded cannot be stained with the usual staining methods. Macroscopically, the cap skin usually appears greasy, greasy or shiny. It often swells up slimy, especially when it is damp.
Trichoderm
In the Trichoderm, the outer hyphae ends are perpendicular to the surface of the hat. The elongated, vertically tall hyphae cells are very reminiscent of upright hair. Therefore the technical term Trichoderm is derived from "Tricho", the Greek word for hair. The hyphae cells are also known as trichoform or hair-like. Some of these hairy hyphae have nearly the same shape and chemical properties as the cystidia of the hymenium . They are therefore also known as dermato- or pileocystidia . Macroscopically, the hat skin usually appears felty or velvety.
Ixotrichoderm
The Ixotrichoderm is a special form of the Trichoderm, in which the outermost hyphae are gelified, that is, they are bound into a gelatinous matrix. Macroscopically, the cap skin resembles the Ixocutis.
Hymeniderm
The hyphae of the hat cover layer are hymeniform or palisadic. The densely packed and vertical, short, club-shaped hyphae are reminiscent of that of the basidia in the hymenium. The hat skin often appears mica or wrinkled and often cracks open. The hymeniderm is also known as the hymenoderm.
Epithelium
In the case of an epithelium, the hyphae of the hat cover layer are broad, more or less rounded or isodiametric and sometimes connected like a chain link. In thin sections, this type is reminiscent of the parenchyma of the higher plants . In the hat skin, however, the hyphae cells are only loosely interwoven. Macroscopically, the hat skin looks like the hymeniderm, but it is often more mica to paper-like matt. Other names for a top layer of round cells are Sphaerocystoderm and Konioderm .
Palisadoderm
Hat skin made up of erect, filamentous, sometimes apically clubbed swollen hyphae ends.
Tomentum
The term tomentum is used for randomly intertwined, long-haired hat surfaces oriented in all directions, mainly on the fruiting bodies of the Aphyllophoranae.
Cortex
The term cortex is used when rough, compacted hyphae structures form crusty surfaces. The term crust is often used in German-language literature for rough, brittle surfaces. These terms are also mainly used for the Aphyllophoranae.
Not established terms
Epi-, sub- and hypostratum
The terms epi-, sub- and hypostratum refer to clearly layered hat clothing for some authors.
Hypoderm
A layer under the superficial cap skin is generally referred to as the hypoderm, usually as a synonym for subcutis.
Epicutis and subcutis
If the top layer of the hat is built up in several layers, the uppermost layer is called the epicutis, while the hyphae that lies under the epicutis and over the hat trama is called the subcutis. Some mycologists prefer to use the term subpellis for this, especially if the overlying layer is not a cutis.
literature
- Marcel Bon (ed.): Parey's book of mushrooms . Franckh-Kosmos Verlag, Stuttgart 2005, ISBN 3-440-09970-9 , pp. 12 .
- Heinrich Dörfelt , Gottfried Jetschke (Ed.): Dictionary of mycology. 2nd Edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2001, ISBN 3-8274-0920-9 .
- Josef Breitenbach, Fred Kränzlin (Ed.): Mushrooms of Switzerland. Contribution to knowledge of the fungal flora in Switzerland. Volume 6: Russulaceae. Milklings, deafblings. Mykologia, Luzern 2005, ISBN 3-85604-060-9 , pp. 16, 20.
